Leg Extension vs Machine Biceps Curl Strength Standards
Compare your leg extension and machine biceps curl against strength standards for your sex and bodyweight. Enter one recent set of 1–12 reps for each lift to see your estimated one-rep maxes, strength levels, next targets, and which lift you should prioritize.
Use each exercise's canonical input: Displayed bilateral machine weight for Leg Extension and Displayed machine or cable resistance for Machine Biceps Curl. Use a strict bilateral leg extension on one dedicated machine with stable hips and torso, a controlled flexed-knee start, near-straight finish, and controlled return and Dedicated machine biceps curl or arm curl machine. You can enter either lift in pounds or kilograms. Each lift is compared with its own standards, so the heavier lift is not automatically the stronger one.
Leg Extension vs Machine Biceps Curl Strength Standards by Bodyweight
Use these tables to compare the estimated one-rep max required for the leg extension and machine biceps curl to reach the same strength level at each listed bodyweight. They show the targets used by the calculator—not a required difference between your leg extension and machine biceps curl.
Choose the men’s or women’s table, find your bodyweight or the closest listed row, then read across to Novice, Intermediate, Advanced, or Elite. Every entry shows Leg Extension / Machine Biceps Curl, with pounds first and kilograms underneath. For a result based on your exact bodyweight and recent sets, use the calculator above; you do not need to test either true one-rep max.
Men’s Leg Extension vs Machine Biceps Curl Standards
How to read the table: The first number is Leg Extension; the second is Machine Biceps Curl. Each number is the lowest estimated one-rep max needed to reach that strength level. Scroll horizontally on smaller screens.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 120 lb 54.4 kg | 49 / 34 lb 22.2 / 15.4 kg | 77 / 52 lb 34.9 / 23.6 kg | 109 / 76 lb 49.4 / 34.5 kg | 143 / 101 lb 64.9 / 45.8 kg |
| 130 lb 59 kg | 52 / 36 lb 23.6 / 16.3 kg | 82 / 54 lb 37.2 / 24.5 kg | 115 / 80 lb 52.2 / 36.3 kg | 151 / 106 lb 68.5 / 48.1 kg |
| 140 lb 63.5 kg | 55 / 38 lb 24.9 / 17.2 kg | 86 / 57 lb 39 / 25.9 kg | 121 / 84 lb 54.9 / 38.1 kg | 158 / 112 lb 71.7 / 50.8 kg |
| 150 lb 68 kg | 57 / 39 lb 25.9 / 17.7 kg | 90 / 60 lb 40.8 / 27.2 kg | 126 / 88 lb 57.2 / 39.9 kg | 166 / 117 lb 75.3 / 53.1 kg |
| 160 lb 72.6 kg | 60 / 41 lb 27.2 / 18.6 kg | 94 / 62 lb 42.6 / 28.1 kg | 132 / 92 lb 59.9 / 41.7 kg | 173 / 122 lb 78.5 / 55.3 kg |
| 170 lb 77.1 kg | 62 / 43 lb 28.1 / 19.5 kg | 97 / 65 lb 44 / 29.5 kg | 137 / 96 lb 62.1 / 43.5 kg | 180 / 127 lb 81.6 / 57.6 kg |
| 180 lb 81.6 kg | 65 / 44 lb 29.5 / 20 kg | 101 / 68 lb 45.8 / 30.8 kg | 143 / 99 lb 64.9 / 44.9 kg | 187 / 132 lb 84.8 / 59.9 kg |
| 190 lb 86.2 kg | 67 / 46 lb 30.4 / 20.9 kg | 105 / 70 lb 47.6 / 31.8 kg | 148 / 103 lb 67.1 / 46.7 kg | 194 / 137 lb 88 / 62.1 kg |
| 200 lb 90.7 kg | 69 / 48 lb 31.3 / 21.8 kg | 109 / 72 lb 49.4 / 32.7 kg | 153 / 107 lb 69.4 / 48.5 kg | 201 / 142 lb 91.2 / 64.4 kg |
| 210 lb 95.3 kg | 72 / 49 lb 32.7 / 22.2 kg | 112 / 75 lb 50.8 / 34 kg | 158 / 110 lb 71.7 / 49.9 kg | 207 / 146 lb 93.9 / 66.2 kg |
| 220 lb 99.8 kg | 74 / 51 lb 33.6 / 23.1 kg | 116 / 77 lb 52.6 / 34.9 kg | 163 / 114 lb 73.9 / 51.7 kg | 214 / 151 lb 97.1 / 68.5 kg |
| 230 lb 104.3 kg | 76 / 52 lb 34.5 / 23.6 kg | 119 / 80 lb 54 / 36.3 kg | 168 / 117 lb 76.2 / 53.1 kg | 220 / 156 lb 99.8 / 70.8 kg |
| 240 lb 108.9 kg | 78 / 54 lb 35.4 / 24.5 kg | 123 / 82 lb 55.8 / 37.2 kg | 173 / 120 lb 78.5 / 54.4 kg | 227 / 160 lb 103 / 72.6 kg |
| 250 lb 113.4 kg | 80 / 55 lb 36.3 / 24.9 kg | 126 / 84 lb 57.2 / 38.1 kg | 178 / 124 lb 80.7 / 56.2 kg | 233 / 165 lb 105.7 / 74.8 kg |
| 260 lb 117.9 kg | 83 / 57 lb 37.6 / 25.9 kg | 129 / 86 lb 58.5 / 39 kg | 182 / 127 lb 82.6 / 57.6 kg | 239 / 169 lb 108.4 / 76.7 kg |
| 270 lb 122.5 kg | 85 / 58 lb 38.6 / 26.3 kg | 133 / 88 lb 60.3 / 39.9 kg | 187 / 130 lb 84.8 / 59 kg | 245 / 173 lb 111.1 / 78.5 kg |
| 280 lb 127 kg | 87 / 60 lb 39.5 / 27.2 kg | 136 / 91 lb 61.7 / 41.3 kg | 192 / 133 lb 87.1 / 60.3 kg | 251 / 177 lb 113.9 / 80.3 kg |
| 290 lb 131.5 kg | 89 / 61 lb 40.4 / 27.7 kg | 139 / 93 lb 63 / 42.2 kg | 196 / 137 lb 88.9 / 62.1 kg | 257 / 182 lb 116.6 / 82.6 kg |
| 300 lb 136.1 kg | 91 / 62 lb 41.3 / 28.1 kg | 142 / 95 lb 64.4 / 43.1 kg | 201 / 140 lb 91.2 / 63.5 kg | 263 / 186 lb 119.3 / 84.4 kg |
Women’s Leg Extension vs Machine Biceps Curl Standards
How to read the table: The first number is Leg Extension; the second is Machine Biceps Curl. Each number is the lowest estimated one-rep max needed to reach that strength level. Scroll horizontally on smaller screens.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 100 lb 45.4 kg | 29 / 18 lb 13.2 / 8.2 kg | 46 / 32 lb 20.9 / 14.5 kg | 69 / 48 lb 31.3 / 21.8 kg | 89 / 66 lb 40.4 / 29.9 kg |
| 110 lb 49.9 kg | 31 / 20 lb 14.1 / 9.1 kg | 49 / 34 lb 22.2 / 15.4 kg | 73 / 51 lb 33.1 / 23.1 kg | 95 / 71 lb 43.1 / 32.2 kg |
| 120 lb 54.4 kg | 33 / 21 lb 15 / 9.5 kg | 52 / 36 lb 23.6 / 16.3 kg | 78 / 54 lb 35.4 / 24.5 kg | 101 / 75 lb 45.8 / 34 kg |
| 130 lb 59 kg | 35 / 22 lb 15.9 / 10 kg | 55 / 38 lb 24.9 / 17.2 kg | 82 / 57 lb 37.2 / 25.9 kg | 106 / 79 lb 48.1 / 35.8 kg |
| 140 lb 63.5 kg | 36 / 23 lb 16.3 / 10.4 kg | 57 / 40 lb 25.9 / 18.1 kg | 86 / 60 lb 39 / 27.2 kg | 112 / 83 lb 50.8 / 37.6 kg |
| 150 lb 68 kg | 38 / 24 lb 17.2 / 10.9 kg | 60 / 42 lb 27.2 / 19.1 kg | 90 / 63 lb 40.8 / 28.6 kg | 117 / 87 lb 53.1 / 39.5 kg |
| 160 lb 72.6 kg | 40 / 25 lb 18.1 / 11.3 kg | 63 / 44 lb 28.6 / 20 kg | 94 / 66 lb 42.6 / 29.9 kg | 122 / 91 lb 55.3 / 41.3 kg |
| 170 lb 77.1 kg | 41 / 26 lb 18.6 / 11.8 kg | 65 / 46 lb 29.5 / 20.9 kg | 98 / 68 lb 44.5 / 30.8 kg | 127 / 95 lb 57.6 / 43.1 kg |
| 180 lb 81.6 kg | 43 / 27 lb 19.5 / 12.2 kg | 68 / 47 lb 30.8 / 21.3 kg | 102 / 71 lb 46.3 / 32.2 kg | 132 / 98 lb 59.9 / 44.5 kg |
| 190 lb 86.2 kg | 44 / 28 lb 20 / 12.7 kg | 70 / 49 lb 31.8 / 22.2 kg | 105 / 74 lb 47.6 / 33.6 kg | 137 / 102 lb 62.1 / 46.3 kg |
| 200 lb 90.7 kg | 46 / 29 lb 20.9 / 13.2 kg | 73 / 51 lb 33.1 / 23.1 kg | 109 / 76 lb 49.4 / 34.5 kg | 142 / 105 lb 64.4 / 47.6 kg |
| 210 lb 95.3 kg | 48 / 30 lb 21.8 / 13.6 kg | 75 / 53 lb 34 / 24 kg | 113 / 79 lb 51.3 / 35.8 kg | 146 / 109 lb 66.2 / 49.4 kg |
| 220 lb 99.8 kg | 49 / 31 lb 22.2 / 14.1 kg | 77 / 54 lb 34.9 / 24.5 kg | 116 / 81 lb 52.6 / 36.7 kg | 151 / 112 lb 68.5 / 50.8 kg |
| 230 lb 104.3 kg | 51 / 32 lb 23.1 / 14.5 kg | 80 / 56 lb 36.3 / 25.4 kg | 120 / 84 lb 54.4 / 38.1 kg | 156 / 116 lb 70.8 / 52.6 kg |
| 240 lb 108.9 kg | 52 / 33 lb 23.6 / 15 kg | 82 / 57 lb 37.2 / 25.9 kg | 123 / 86 lb 55.8 / 39 kg | 160 / 119 lb 72.6 / 54 kg |
How Your Leg Extension vs Machine Biceps Curl Result Is Calculated
The calculator estimates each max, rates it against the standards for that exercise and bodyweight, then compares the two ratings. Here is the complete process.
1. Estimate a one-rep max from each set
For one rep, it uses the weight entered. For 2–12 reps, it runs both formulas and keeps the lower, less aggressive estimate.
- 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. Estimates are more dependable from clean, difficult, lower-rep sets. See the Back-squat formula validation study and Published discussion of back-squat one-rep-max prediction research.
2. Find the leg extension strength level
The leg extension standards use the sex-specific standards from the individual Leg Extension tool. Targets begin at 190 lb for men and 150 lb for women, then adjust to your exact bodyweight: reference target × (user bodyweight ÷ reference bodyweight) to the two-thirds power.
The target rises more slowly than bodyweight so heavier lifters are expected to extend more displayed resistance without requiring strength to increase pound for pound.
3. Find the machine biceps curl strength level
The standards use the sex-specific thresholds from the individual Machine Biceps Curl tool. Targets begin at 190 lb for men and 150 lb for women, then adjust to your exact bodyweight: reference target × (user bodyweight ÷ reference bodyweight) to the two-thirds power.
The target rises more slowly than bodyweight so larger lifters are expected to lift more without requiring strength to increase pound for pound.
4. Compare the two results
Each max receives a level from Beginner through Elite. The lower-level lift is the priority. If the levels match, a priority appears only when one lift is at least 10 points farther from its next level. Otherwise, the result is Balanced.
The result shows which lift ranks lower, not why. Technique, fatigue, training history, and set quality can affect it. Age range is recorded anonymously but does not change the standards.
| Stage | What happens |
|---|---|
| Estimate each max | Use the entered weight for 1 rep; for 2–12 reps, keep the lower formula result. |
| Rate the leg extension | Adjust leg extension targets to exact bodyweight with the two-thirds rule. |
| Rate the machine biceps curl | Use the canonical estimated max and adjust targets to exact bodyweight with the approved two-thirds rule. |
| Compare different levels | Name the lower-level lift as the priority. |
| Compare matching levels | Use Balanced unless the difference in progress toward the next level reaches 10 points. |
Use the calculator above to see both estimated maxes, strength levels, the priority or Balanced result, and both next-level targets.
How Men’s Leg Extension and Machine Biceps Curl Standards Differ
How to read both charts: Choose a strength level, find bodyweight along the bottom, and follow that level’s line. Zero means the two standards are equal. Above zero means the machine biceps curl standard is higher; below zero means the leg extension standard is higher. On a phone, swipe the chart left and right to inspect the full-size lines and labels. The tables provide the exact pounds and kilograms.
What the men’s data shows:
The standards come closest at 120 lb.
Novice, Intermediate, Advanced, and Elite at every displayed bodyweight.
19.1 → 34.9 kg from 120 to 300 lb bodyweight.
How to read the table: Every number is the machine biceps curl standard minus the leg extension standard. A plus sign means the machine biceps curl standard is higher. A minus sign means the leg extension standard is higher.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 120 lb 54.4 kg | −15 lb −6.8 kg | −25 lb −11.3 kg | −33 lb −14.9 kg | −42 lb −19.1 kg |
| 130 lb 59 kg | −16 lb −7.3 kg | −28 lb −12.7 kg | −35 lb −15.9 kg | −45 lb −20.4 kg |
| 140 lb 63.5 kg | −17 lb −7.7 kg | −29 lb −13.1 kg | −37 lb −16.8 kg | −46 lb −20.9 kg |
| 150 lb 68 kg | −18 lb −8.2 kg | −30 lb −13.6 kg | −38 lb −17.3 kg | −49 lb −22.2 kg |
| 160 lb 72.6 kg | −19 lb −8.6 kg | −32 lb −14.5 kg | −40 lb −18.2 kg | −51 lb −23.2 kg |
| 170 lb 77.1 kg | −19 lb −8.6 kg | −32 lb −14.5 kg | −41 lb −18.6 kg | −53 lb −24 kg |
| 180 lb 81.6 kg | −21 lb −9.5 kg | −33 lb −15 kg | −44 lb −20 kg | −55 lb −24.9 kg |
| 190 lb 86.2 kg | −21 lb −9.5 kg | −35 lb −15.8 kg | −45 lb −20.4 kg | −57 lb −25.9 kg |
| 200 lb 90.7 kg | −21 lb −9.5 kg | −37 lb −16.7 kg | −46 lb −20.9 kg | −59 lb −26.8 kg |
| 210 lb 95.3 kg | −23 lb −10.5 kg | −37 lb −16.8 kg | −48 lb −21.8 kg | −61 lb −27.7 kg |
| 220 lb 99.8 kg | −23 lb −10.5 kg | −39 lb −17.7 kg | −49 lb −22.2 kg | −63 lb −28.6 kg |
| 230 lb 104.3 kg | −24 lb −10.9 kg | −39 lb −17.7 kg | −51 lb −23.1 kg | −64 lb −29 kg |
| 240 lb 108.9 kg | −24 lb −10.9 kg | −41 lb −18.6 kg | −53 lb −24.1 kg | −67 lb −30.4 kg |
| 250 lb 113.4 kg | −25 lb −11.4 kg | −42 lb −19.1 kg | −54 lb −24.5 kg | −68 lb −30.9 kg |
| 260 lb 117.9 kg | −26 lb −11.7 kg | −43 lb −19.5 kg | −55 lb −25 kg | −70 lb −31.7 kg |
| 270 lb 122.5 kg | −27 lb −12.3 kg | −45 lb −20.4 kg | −57 lb −25.8 kg | −72 lb −32.6 kg |
| 280 lb 127 kg | −27 lb −12.3 kg | −45 lb −20.4 kg | −59 lb −26.8 kg | −74 lb −33.6 kg |
| 290 lb 131.5 kg | −28 lb −12.7 kg | −46 lb −20.8 kg | −59 lb −26.8 kg | −75 lb −34 kg |
| 300 lb 136.1 kg | −29 lb −13.2 kg | −47 lb −21.3 kg | −61 lb −27.7 kg | −77 lb −34.9 kg |
How Women’s Leg Extension and Machine Biceps Curl Standards Differ
What the women’s data shows:
The standards come closest at 100 lb.
Novice, Intermediate, Advanced, and Elite at every displayed bodyweight.
10.5 → 18.6 kg from 100 to 240 lb bodyweight.
How to read the table: Every number is the machine biceps curl standard minus the leg extension standard. A plus sign means the machine biceps curl standard is higher. A minus sign means the leg extension standard is higher.
| Bodyweight | Novice | Intermediate | Advanced | Elite |
|---|---|---|---|---|
| 100 lb 45.4 kg | −11 lb −5 kg | −14 lb −6.4 kg | −21 lb −9.5 kg | −23 lb −10.5 kg |
| 110 lb 49.9 kg | −11 lb −5 kg | −15 lb −6.8 kg | −22 lb −10 kg | −24 lb −10.9 kg |
| 120 lb 54.4 kg | −12 lb −5.5 kg | −16 lb −7.3 kg | −24 lb −10.9 kg | −26 lb −11.8 kg |
| 130 lb 59 kg | −13 lb −5.9 kg | −17 lb −7.7 kg | −25 lb −11.3 kg | −27 lb −12.3 kg |
| 140 lb 63.5 kg | −13 lb −5.9 kg | −17 lb −7.8 kg | −26 lb −11.8 kg | −29 lb −13.2 kg |
| 150 lb 68 kg | −14 lb −6.3 kg | −18 lb −8.1 kg | −27 lb −12.2 kg | −30 lb −13.6 kg |
| 160 lb 72.6 kg | −15 lb −6.8 kg | −19 lb −8.6 kg | −28 lb −12.7 kg | −31 lb −14 kg |
| 170 lb 77.1 kg | −15 lb −6.8 kg | −19 lb −8.6 kg | −30 lb −13.7 kg | −32 lb −14.5 kg |
| 180 lb 81.6 kg | −16 lb −7.3 kg | −21 lb −9.5 kg | −31 lb −14.1 kg | −34 lb −15.4 kg |
| 190 lb 86.2 kg | −16 lb −7.3 kg | −21 lb −9.6 kg | −31 lb −14 kg | −35 lb −15.8 kg |
| 200 lb 90.7 kg | −17 lb −7.7 kg | −22 lb −10 kg | −33 lb −14.9 kg | −37 lb −16.8 kg |
| 210 lb 95.3 kg | −18 lb −8.2 kg | −22 lb −10 kg | −34 lb −15.5 kg | −37 lb −16.8 kg |
| 220 lb 99.8 kg | −18 lb −8.1 kg | −23 lb −10.4 kg | −35 lb −15.9 kg | −39 lb −17.7 kg |
| 230 lb 104.3 kg | −19 lb −8.6 kg | −24 lb −10.9 kg | −36 lb −16.3 kg | −40 lb −18.2 kg |
| 240 lb 108.9 kg | −19 lb −8.6 kg | −25 lb −11.3 kg | −37 lb −16.8 kg | −41 lb −18.6 kg |
Leg Extension and Machine Biceps Curl Exercises Used by This Calculator
This calculator uses a bilateral machine leg extension and a strict machine biceps curl test. Use strict canonical Leg Extension and Machine Biceps Curl tests. Do not mix variations, assistance, partial range, momentum, or different load conventions.
Use a strict bilateral leg extension
Use both legs on the same dedicated machine and setup. Keep the hips, thighs, and torso stable, extend from a controlled flexed-knee start to a near-straight finish, and return under control. Do not enter per-leg load, a single-leg rep, partial pulse, bounced stack, cable or band extension, squat, or leg press.
Use the canonical Machine Biceps Curl setup and load convention
Dedicated machine biceps curl or arm curl machine Enter selected or loaded bilateral machine resistance Same machine, seat setting, arm pad or handle setup, load, and range across the set Start each rep from a controlled near-extended elbow position Torso, hips, shoulders, and upper arms stay stable according to the machine design Wrists stay controlled on the handles or grips Curl both handles through the machine-guided elbow-flexion path Clear controlled top curl position, no handle yanking Controlled return to the same near-extended bottom range No dumbbell, barbell, EZ-bar, cable, hammer curl, reverse curl, row, pull-up, or free-weight preacher substitution No stack bounce, machine-stop rebound, torso heave, shoulder swing, hip lift, or partial reps
Enter one recent Leg Extension result and one recent Machine Biceps Curl result
Use each exercise’s canonical input: Displayed bilateral machine weight for Leg Extension and Displayed machine or cable resistance for Machine Biceps Curl.
Related Tools
- Leg Extension — View the individual Leg Extension standards and next strength-level target.
- Machine Biceps Curl — View the individual Machine Biceps Curl standards and next strength-level target.
- Seated Leg Curl — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Lying Leg Curl — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Leg Press (45° Sled) — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.
- Machine Hack Squat — Use this related standards tool to compare a registry-approved neighboring exercise without mixing its result into this comparison.