Seated Leg Curl vs Bodyweight Back Extension Strength Standards
Compare your seated leg curl and bodyweight back extension against strength standards for your sex, age range, and bodyweight. Enter one result for each exercise to see your strength levels, next target, and which exercise is the priority.
Use each exercise's canonical input: Displayed machine or stack weight for Seated Leg Curl and No external load for Bodyweight Back Extension. Use a strict, repeatable seated leg curl set that follows the canonical setup, range, and lockout rules; use a strict, repeatable bodyweight back extension test using the canonical setup, range, and finish rules. Repetitions are never converted into weight. Each exercise keeps its own measurement type. Age range changes only an exercise whose standards use age.
Seated Leg Curl vs Bodyweight Back Extension Strength Standards by Bodyweight
These tables show the minimum result each exercise needs to reach Novice, Intermediate, Advanced, and Elite. Weight-based standards are shown in pounds and kilograms. Direct-performance standards remain strict repetitions or seconds and show every applicable age range.
Find your bodyweight in the men’s or women’s table, then read across the strength levels. Results measured in weight, repetitions, or seconds are not meant to match and are never converted into one another. Use the calculator for your exact inputs and a direct comparison of the strength levels.
Men’s Seated Leg Curl vs Bodyweight Back Extension Standards
How to read the table: Each table entry lists the minimum result for both exercises. Weight-based targets show pounds and kilograms; direct-performance targets show strict repetitions or seconds for each age range. Scroll horizontally on smaller screens.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 120 lb 54.4 kg | Seated Leg Curl:39 lb17.7 kg Bodyweight Back Extension:Under 30: 12 reps30–39: 11 reps40–49: 10 reps50–59: 8 reps60+: 6 reps | Seated Leg Curl:64 lb29 kg Bodyweight Back Extension:Under 30: 30 reps30–39: 27 reps40–49: 24 reps50–59: 20 reps60+: 15 reps | Seated Leg Curl:95 lb43.1 kg Bodyweight Back Extension:Under 30: 55 reps30–39: 50 reps40–49: 44 reps50–59: 36 reps60+: 28 reps | Seated Leg Curl:126 lb57.2 kg Bodyweight Back Extension:Under 30: 85 reps30–39: 77 reps40–49: 68 reps50–59: 55 reps60+: 43 reps |
| 130 lb 59 kg | Seated Leg Curl:41 lb18.6 kg Bodyweight Back Extension:Under 30: 12 reps30–39: 11 reps40–49: 10 reps50–59: 8 reps60+: 6 reps | Seated Leg Curl:68 lb30.8 kg Bodyweight Back Extension:Under 30: 30 reps30–39: 27 reps40–49: 24 reps50–59: 20 reps60+: 15 reps | Seated Leg Curl:100 lb45.4 kg Bodyweight Back Extension:Under 30: 55 reps30–39: 50 reps40–49: 44 reps50–59: 36 reps60+: 28 reps | Seated Leg Curl:133 lb60.3 kg Bodyweight Back Extension:Under 30: 85 reps30–39: 77 reps40–49: 68 reps50–59: 55 reps60+: 43 reps |
| 140 lb 63.5 kg | Seated Leg Curl:43 lb19.5 kg Bodyweight Back Extension:Under 30: 12 reps30–39: 11 reps40–49: 10 reps50–59: 8 reps60+: 6 reps | Seated Leg Curl:71 lb32.2 kg Bodyweight Back Extension:Under 30: 30 reps30–39: 27 reps40–49: 24 reps50–59: 20 reps60+: 15 reps | Seated Leg Curl:105 lb47.6 kg Bodyweight Back Extension:Under 30: 55 reps30–39: 50 reps40–49: 44 reps50–59: 36 reps60+: 28 reps | Seated Leg Curl:140 lb63.5 kg Bodyweight Back Extension:Under 30: 85 reps30–39: 77 reps40–49: 68 reps50–59: 55 reps60+: 43 reps |
| 150 lb 68 kg | Seated Leg Curl:45 lb20.4 kg Bodyweight Back Extension:Under 30: 10 reps30–39: 9 reps40–49: 8 reps50–59: 7 reps60+: 5 reps | Seated Leg Curl:74 lb33.6 kg Bodyweight Back Extension:Under 30: 25 reps30–39: 23 reps40–49: 20 reps50–59: 16 reps60+: 13 reps | Seated Leg Curl:110 lb49.9 kg Bodyweight Back Extension:Under 30: 46 reps30–39: 41 reps40–49: 37 reps50–59: 30 reps60+: 23 reps | Seated Leg Curl:146 lb66.2 kg Bodyweight Back Extension:Under 30: 72 reps30–39: 65 reps40–49: 58 reps50–59: 47 reps60+: 36 reps |
| 160 lb 72.6 kg | Seated Leg Curl:47 lb21.3 kg Bodyweight Back Extension:Under 30: 10 reps30–39: 9 reps40–49: 8 reps50–59: 7 reps60+: 5 reps | Seated Leg Curl:78 lb35.4 kg Bodyweight Back Extension:Under 30: 25 reps30–39: 23 reps40–49: 20 reps50–59: 16 reps60+: 13 reps | Seated Leg Curl:115 lb52.2 kg Bodyweight Back Extension:Under 30: 46 reps30–39: 41 reps40–49: 37 reps50–59: 30 reps60+: 23 reps | Seated Leg Curl:152 lb68.9 kg Bodyweight Back Extension:Under 30: 72 reps30–39: 65 reps40–49: 58 reps50–59: 47 reps60+: 36 reps |
| 170 lb 77.1 kg | Seated Leg Curl:49 lb22.2 kg Bodyweight Back Extension:Under 30: 10 reps30–39: 9 reps40–49: 8 reps50–59: 7 reps60+: 5 reps | Seated Leg Curl:81 lb36.7 kg Bodyweight Back Extension:Under 30: 25 reps30–39: 23 reps40–49: 20 reps50–59: 16 reps60+: 13 reps | Seated Leg Curl:120 lb54.4 kg Bodyweight Back Extension:Under 30: 46 reps30–39: 41 reps40–49: 37 reps50–59: 30 reps60+: 23 reps | Seated Leg Curl:159 lb72.1 kg Bodyweight Back Extension:Under 30: 72 reps30–39: 65 reps40–49: 58 reps50–59: 47 reps60+: 36 reps |
| 180 lb 81.6 kg | Seated Leg Curl:51 lb23.1 kg Bodyweight Back Extension:Under 30: 10 reps30–39: 9 reps40–49: 8 reps50–59: 7 reps60+: 5 reps | Seated Leg Curl:84 lb38.1 kg Bodyweight Back Extension:Under 30: 25 reps30–39: 23 reps40–49: 20 reps50–59: 16 reps60+: 13 reps | Seated Leg Curl:124 lb56.2 kg Bodyweight Back Extension:Under 30: 46 reps30–39: 41 reps40–49: 37 reps50–59: 30 reps60+: 23 reps | Seated Leg Curl:165 lb74.8 kg Bodyweight Back Extension:Under 30: 72 reps30–39: 65 reps40–49: 58 reps50–59: 47 reps60+: 36 reps |
| 190 lb 86.2 kg | Seated Leg Curl:53 lb24 kg Bodyweight Back Extension:Under 30: 10 reps30–39: 9 reps40–49: 8 reps50–59: 7 reps60+: 5 reps | Seated Leg Curl:87 lb39.5 kg Bodyweight Back Extension:Under 30: 25 reps30–39: 23 reps40–49: 20 reps50–59: 16 reps60+: 13 reps | Seated Leg Curl:129 lb58.5 kg Bodyweight Back Extension:Under 30: 46 reps30–39: 41 reps40–49: 37 reps50–59: 30 reps60+: 23 reps | Seated Leg Curl:171 lb77.6 kg Bodyweight Back Extension:Under 30: 72 reps30–39: 65 reps40–49: 58 reps50–59: 47 reps60+: 36 reps |
| 200 lb 90.7 kg | Seated Leg Curl:55 lb24.9 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:90 lb40.8 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:133 lb60.3 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:177 lb80.3 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 210 lb 95.3 kg | Seated Leg Curl:57 lb25.9 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:93 lb42.2 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:138 lb62.6 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:183 lb83 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 220 lb 99.8 kg | Seated Leg Curl:58 lb26.3 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:96 lb43.5 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:142 lb64.4 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:189 lb85.7 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 230 lb 104.3 kg | Seated Leg Curl:60 lb27.2 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:99 lb44.9 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:147 lb66.7 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:194 lb88 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 240 lb 108.9 kg | Seated Leg Curl:62 lb28.1 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:102 lb46.3 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:151 lb68.5 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:200 lb90.7 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 250 lb 113.4 kg | Seated Leg Curl:64 lb29 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:104 lb47.2 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:155 lb70.3 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:205 lb93 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 260 lb 117.9 kg | Seated Leg Curl:65 lb29.5 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:107 lb48.5 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:159 lb72.1 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:211 lb95.7 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 270 lb 122.5 kg | Seated Leg Curl:67 lb30.4 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:110 lb49.9 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:163 lb73.9 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:216 lb98 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 280 lb 127 kg | Seated Leg Curl:69 lb31.3 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:113 lb51.3 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:167 lb75.7 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:221 lb100.2 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 290 lb 131.5 kg | Seated Leg Curl:70 lb31.8 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:115 lb52.2 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:171 lb77.6 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:227 lb103 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
| 300 lb 136.1 kg | Seated Leg Curl:72 lb32.7 kg Bodyweight Back Extension:Under 30: 8 reps30–39: 7 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:118 lb53.5 kg Bodyweight Back Extension:Under 30: 20 reps30–39: 18 reps40–49: 16 reps50–59: 13 reps60+: 10 reps | Seated Leg Curl:175 lb79.4 kg Bodyweight Back Extension:Under 30: 38 reps30–39: 34 reps40–49: 30 reps50–59: 25 reps60+: 19 reps | Seated Leg Curl:232 lb105.2 kg Bodyweight Back Extension:Under 30: 60 reps30–39: 54 reps40–49: 48 reps50–59: 39 reps60+: 30 reps |
Women’s Seated Leg Curl vs Bodyweight Back Extension Standards
How to read the table: Each table entry lists the minimum result for both exercises. Weight-based targets show pounds and kilograms; direct-performance targets show strict repetitions or seconds for each age range. Scroll horizontally on smaller screens.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 100 lb 45.4 kg | Seated Leg Curl:23 lb10.4 kg Bodyweight Back Extension:Under 30: 11 reps30–39: 10 reps40–49: 9 reps50–59: 7 reps60+: 6 reps | Seated Leg Curl:39 lb17.7 kg Bodyweight Back Extension:Under 30: 28 reps30–39: 25 reps40–49: 22 reps50–59: 18 reps60+: 14 reps | Seated Leg Curl:60 lb27.2 kg Bodyweight Back Extension:Under 30: 50 reps30–39: 45 reps40–49: 40 reps50–59: 33 reps60+: 25 reps | Seated Leg Curl:80 lb36.3 kg Bodyweight Back Extension:Under 30: 78 reps30–39: 70 reps40–49: 62 reps50–59: 51 reps60+: 39 reps |
| 110 lb 49.9 kg | Seated Leg Curl:24 lb10.9 kg Bodyweight Back Extension:Under 30: 11 reps30–39: 10 reps40–49: 9 reps50–59: 7 reps60+: 6 reps | Seated Leg Curl:41 lb18.6 kg Bodyweight Back Extension:Under 30: 28 reps30–39: 25 reps40–49: 22 reps50–59: 18 reps60+: 14 reps | Seated Leg Curl:63 lb28.6 kg Bodyweight Back Extension:Under 30: 50 reps30–39: 45 reps40–49: 40 reps50–59: 33 reps60+: 25 reps | Seated Leg Curl:85 lb38.6 kg Bodyweight Back Extension:Under 30: 78 reps30–39: 70 reps40–49: 62 reps50–59: 51 reps60+: 39 reps |
| 120 lb 54.4 kg | Seated Leg Curl:26 lb11.8 kg Bodyweight Back Extension:Under 30: 9 reps30–39: 8 reps40–49: 7 reps50–59: 6 reps60+: 5 reps | Seated Leg Curl:44 lb20 kg Bodyweight Back Extension:Under 30: 23 reps30–39: 21 reps40–49: 18 reps50–59: 15 reps60+: 12 reps | Seated Leg Curl:67 lb30.4 kg Bodyweight Back Extension:Under 30: 42 reps30–39: 38 reps40–49: 34 reps50–59: 27 reps60+: 21 reps | Seated Leg Curl:90 lb40.8 kg Bodyweight Back Extension:Under 30: 66 reps30–39: 59 reps40–49: 53 reps50–59: 43 reps60+: 33 reps |
| 130 lb 59 kg | Seated Leg Curl:27 lb12.2 kg Bodyweight Back Extension:Under 30: 9 reps30–39: 8 reps40–49: 7 reps50–59: 6 reps60+: 5 reps | Seated Leg Curl:46 lb20.9 kg Bodyweight Back Extension:Under 30: 23 reps30–39: 21 reps40–49: 18 reps50–59: 15 reps60+: 12 reps | Seated Leg Curl:71 lb32.2 kg Bodyweight Back Extension:Under 30: 42 reps30–39: 38 reps40–49: 34 reps50–59: 27 reps60+: 21 reps | Seated Leg Curl:95 lb43.1 kg Bodyweight Back Extension:Under 30: 66 reps30–39: 59 reps40–49: 53 reps50–59: 43 reps60+: 33 reps |
| 140 lb 63.5 kg | Seated Leg Curl:29 lb13.2 kg Bodyweight Back Extension:Under 30: 9 reps30–39: 8 reps40–49: 7 reps50–59: 6 reps60+: 5 reps | Seated Leg Curl:49 lb22.2 kg Bodyweight Back Extension:Under 30: 23 reps30–39: 21 reps40–49: 18 reps50–59: 15 reps60+: 12 reps | Seated Leg Curl:74 lb33.6 kg Bodyweight Back Extension:Under 30: 42 reps30–39: 38 reps40–49: 34 reps50–59: 27 reps60+: 21 reps | Seated Leg Curl:100 lb45.4 kg Bodyweight Back Extension:Under 30: 66 reps30–39: 59 reps40–49: 53 reps50–59: 43 reps60+: 33 reps |
| 150 lb 68 kg | Seated Leg Curl:30 lb13.6 kg Bodyweight Back Extension:Under 30: 9 reps30–39: 8 reps40–49: 7 reps50–59: 6 reps60+: 5 reps | Seated Leg Curl:51 lb23.1 kg Bodyweight Back Extension:Under 30: 23 reps30–39: 21 reps40–49: 18 reps50–59: 15 reps60+: 12 reps | Seated Leg Curl:78 lb35.4 kg Bodyweight Back Extension:Under 30: 42 reps30–39: 38 reps40–49: 34 reps50–59: 27 reps60+: 21 reps | Seated Leg Curl:105 lb47.6 kg Bodyweight Back Extension:Under 30: 66 reps30–39: 59 reps40–49: 53 reps50–59: 43 reps60+: 33 reps |
| 160 lb 72.6 kg | Seated Leg Curl:31 lb14.1 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:53 lb24 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:81 lb36.7 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:110 lb49.9 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 170 lb 77.1 kg | Seated Leg Curl:33 lb15 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:55 lb24.9 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:85 lb38.6 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:114 lb51.7 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 180 lb 81.6 kg | Seated Leg Curl:34 lb15.4 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:58 lb26.3 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:88 lb39.9 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:119 lb54 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 190 lb 86.2 kg | Seated Leg Curl:35 lb15.9 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:60 lb27.2 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:91 lb41.3 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:123 lb55.8 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 200 lb 90.7 kg | Seated Leg Curl:36 lb16.3 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:62 lb28.1 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:94 lb42.6 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:127 lb57.6 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 210 lb 95.3 kg | Seated Leg Curl:38 lb17.2 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:64 lb29 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:98 lb44.5 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:131 lb59.4 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 220 lb 99.8 kg | Seated Leg Curl:39 lb17.7 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:66 lb29.9 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:101 lb45.8 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:136 lb61.7 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 230 lb 104.3 kg | Seated Leg Curl:40 lb18.1 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:68 lb30.8 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:104 lb47.2 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:140 lb63.5 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
| 240 lb 108.9 kg | Seated Leg Curl:41 lb18.6 kg Bodyweight Back Extension:Under 30: 7 reps30–39: 6 reps40–49: 6 reps50–59: 5 reps60+: 4 reps | Seated Leg Curl:70 lb31.8 kg Bodyweight Back Extension:Under 30: 18 reps30–39: 16 reps40–49: 14 reps50–59: 12 reps60+: 9 reps | Seated Leg Curl:107 lb48.5 kg Bodyweight Back Extension:Under 30: 34 reps30–39: 31 reps40–49: 27 reps50–59: 22 reps60+: 17 reps | Seated Leg Curl:144 lb65.3 kg Bodyweight Back Extension:Under 30: 54 reps30–39: 49 reps40–49: 43 reps50–59: 35 reps60+: 27 reps |
How Your Seated Leg Curl vs Bodyweight Back Extension Result Is Calculated
The two exercises can use different measurements. The calculator rates each result against the standards for that exercise first, then compares the resulting strength levels and progress toward the next level. It never invents a reps-to-weight conversion.
1. Estimate the weight-based result
For Seated Leg Curl, one rep uses the weight entered. For 2–12 reps, the calculator runs both estimates and keeps the lower result.
- Epley: weight × (1 + reps ÷ 30)
- Brzycki: weight × 36 ÷ (37 − reps)
A published back-squat study supports estimated-max prediction under its study conditions. It does not independently validate every exercise or population used by this comparison.
2. Rate the Seated Leg Curl result
The standards use the sex-specific targets from the individual Seated Leg Curl tool. The target adjusts to bodyweight using reference target × (user bodyweight ÷ reference bodyweight) to the two-thirds power.
3. Rate the Bodyweight Back Extension result
The canonical repetition thresholds map the strict set to a strength tier; no reps-to-weight conversion is used. The calculator uses one continuous strict bodyweight back extension set scored by repetitions and does not convert the repetitions into an estimated weight.
4. Compare strength level and progress
The lower strength level is the priority. When both exercises reach the same level, a priority appears only when one is at least 10 points farther from its next target. Otherwise, the result is Balanced. Age range changes only the exercise whose standards include age; it remains an analytics field for the other exercise.
| Stage | What happens |
|---|---|
| Rate the seated leg curl | Adjust seated leg curl targets to exact bodyweight with the two-thirds rule. Measurement: estimated one-rep max. |
| Rate the bodyweight back extension | Rate strict bodyweight back extension repetitions without converting them into weight. Measurement: Strict bodyweight back extension reps. |
| Compare levels | Use each exercise’s own level and next target; do not compare or divide results that use different measurements. |
How Men’s Seated Leg Curl and Bodyweight Back Extension Standards Differ
What the men’s standards show:
Elite weight targets from 120 to 300 lb bodyweight.
Elite direct-performance targets from the youngest to oldest listed age range at 120 lb bodyweight.
Raw repetitions, seconds, and weights are not divided or converted. The calculator compares each exercise’s canonical tier and progress within that tier.
The exact table above is the correct way to inspect direct or unlike measurements. A pounds-difference chart would be invalid because repetitions, seconds, and estimated weight do not share a unit.
How Women’s Seated Leg Curl and Bodyweight Back Extension Standards Differ
What the women’s standards show:
Elite weight targets from 100 to 240 lb bodyweight.
Elite direct-performance targets from the youngest to oldest listed age range at 100 lb bodyweight.
Raw repetitions, seconds, and weights are not divided or converted. The calculator compares each exercise’s canonical tier and progress within that tier.
Use the calculator to apply the correct age range and exact bodyweight before comparing the two strength levels.
Seated Leg Curl and Bodyweight Back Extension Exercises Used by This Calculator
This calculator uses a strict seated leg curl and a strict bodyweight back extension. Use strict canonical Seated Leg Curl and Bodyweight Back Extension tests. Do not mix variations, assistance, partial range, momentum, or different load conventions.
Use a strict, repeatable Seated Leg Curl
Selected or loaded machine resistance is used Enter total bilateral load, not per-leg load Do not add bodyweight to the entered load Strict seated bilateral machine leg curl Thigh restraint and lower-leg pad stay consistent Back, hips, pelvis, thighs, seat, and pad position stay stable Enter displayed machine or stack weight. Keep the same equipment and setup when retesting.
Use a strict, repeatable Bodyweight Back Extension
Follow the individual Bodyweight Back Extension calculator’s canonical setup, load convention, range of motion, and finish rules. Keep the same setup when retesting.
Enter one recent Seated Leg Curl result and one recent Bodyweight Back Extension result
Use each exercise’s canonical input: Displayed machine or stack weight for Seated Leg Curl and No external load for Bodyweight Back Extension.
Related Tools
- Seated Leg Curl — View the individual Seated Leg Curl standards and next strength-level target.
- Bodyweight Back Extension Strength Standards — View the individual Bodyweight Back Extension standards and next strength-level target.
- Leg Extension — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Romanian Deadlift — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Barbell Stiff-Leg Deadlift — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Barbell Good Morning — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.