Endura

Lying Leg Curl vs Leg Extension Strength Standards

Compare your lying leg curl and leg extension 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.

Enter the canonical working weight and a whole number of strict repetitions for each exercise. Pounds and kilograms can be mixed. Use a strict, repeatable lying leg curl set that follows the canonical setup, range, and lockout rules and 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. 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.

Lying Leg Curl vs Leg Extension Strength Standards by Bodyweight

Use these tables to compare the estimated one-rep max required for the lying leg curl and leg extension to reach the same strength level at each listed bodyweight. They show the targets used by the calculator—not a required difference between your lying leg curl and leg extension.

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 Lying Leg Curl / Leg Extension, 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 Lying Leg Curl vs Leg Extension Standards

How to read the table: The first number is Lying Leg Curl; the second is Leg Extension. Each number is the lowest estimated one-rep max needed to reach that strength level. Scroll horizontally on smaller screens.

BodyweightNoviceIntermediateAdvancedElite
120 lb
54.4 kg
36 / 49 lb
16.3 / 22.2 kg
60 / 77 lb
27.2 / 34.9 kg
90 / 109 lb
40.8 / 49.4 kg
118 / 143 lb
53.5 / 64.9 kg
130 lb
59 kg
38 / 52 lb
17.2 / 23.6 kg
64 / 82 lb
29 / 37.2 kg
95 / 115 lb
43.1 / 52.2 kg
124 / 151 lb
56.2 / 68.5 kg
140 lb
63.5 kg
40 / 55 lb
18.1 / 24.9 kg
67 / 86 lb
30.4 / 39 kg
100 / 121 lb
45.4 / 54.9 kg
131 / 158 lb
59.4 / 71.7 kg
150 lb
68 kg
42 / 57 lb
19.1 / 25.9 kg
70 / 90 lb
31.8 / 40.8 kg
104 / 126 lb
47.2 / 57.2 kg
137 / 166 lb
62.1 / 75.3 kg
160 lb
72.6 kg
44 / 60 lb
20 / 27.2 kg
73 / 94 lb
33.1 / 42.6 kg
109 / 132 lb
49.4 / 59.9 kg
143 / 173 lb
64.9 / 78.5 kg
170 lb
77.1 kg
45 / 62 lb
20.4 / 28.1 kg
76 / 97 lb
34.5 / 44 kg
113 / 137 lb
51.3 / 62.1 kg
149 / 180 lb
67.6 / 81.6 kg
180 lb
81.6 kg
47 / 65 lb
21.3 / 29.5 kg
79 / 101 lb
35.8 / 45.8 kg
118 / 143 lb
53.5 / 64.9 kg
154 / 187 lb
69.9 / 84.8 kg
190 lb
86.2 kg
49 / 67 lb
22.2 / 30.4 kg
82 / 105 lb
37.2 / 47.6 kg
122 / 148 lb
55.3 / 67.1 kg
160 / 194 lb
72.6 / 88 kg
200 lb
90.7 kg
51 / 69 lb
23.1 / 31.3 kg
85 / 109 lb
38.6 / 49.4 kg
126 / 153 lb
57.2 / 69.4 kg
166 / 201 lb
75.3 / 91.2 kg
210 lb
95.3 kg
52 / 72 lb
23.6 / 32.7 kg
88 / 112 lb
39.9 / 50.8 kg
130 / 158 lb
59 / 71.7 kg
171 / 207 lb
77.6 / 93.9 kg
220 lb
99.8 kg
54 / 74 lb
24.5 / 33.6 kg
90 / 116 lb
40.8 / 52.6 kg
135 / 163 lb
61.2 / 73.9 kg
176 / 214 lb
79.8 / 97.1 kg
230 lb
104.3 kg
56 / 76 lb
25.4 / 34.5 kg
93 / 119 lb
42.2 / 54 kg
139 / 168 lb
63 / 76.2 kg
182 / 220 lb
82.6 / 99.8 kg
240 lb
108.9 kg
57 / 78 lb
25.9 / 35.4 kg
96 / 123 lb
43.5 / 55.8 kg
143 / 173 lb
64.9 / 78.5 kg
187 / 227 lb
84.8 / 103 kg
250 lb
113.4 kg
59 / 80 lb
26.8 / 36.3 kg
98 / 126 lb
44.5 / 57.2 kg
146 / 178 lb
66.2 / 80.7 kg
192 / 233 lb
87.1 / 105.7 kg
260 lb
117.9 kg
60 / 83 lb
27.2 / 37.6 kg
101 / 129 lb
45.8 / 58.5 kg
150 / 182 lb
68 / 82.6 kg
197 / 239 lb
89.4 / 108.4 kg
270 lb
122.5 kg
62 / 85 lb
28.1 / 38.6 kg
104 / 133 lb
47.2 / 60.3 kg
154 / 187 lb
69.9 / 84.8 kg
202 / 245 lb
91.6 / 111.1 kg
280 lb
127 kg
63 / 87 lb
28.6 / 39.5 kg
106 / 136 lb
48.1 / 61.7 kg
158 / 192 lb
71.7 / 87.1 kg
207 / 251 lb
93.9 / 113.9 kg
290 lb
131.5 kg
65 / 89 lb
29.5 / 40.4 kg
109 / 139 lb
49.4 / 63 kg
162 / 196 lb
73.5 / 88.9 kg
212 / 257 lb
96.2 / 116.6 kg
300 lb
136.1 kg
66 / 91 lb
29.9 / 41.3 kg
111 / 142 lb
50.3 / 64.4 kg
165 / 201 lb
74.8 / 91.2 kg
217 / 263 lb
98.4 / 119.3 kg

Women’s Lying Leg Curl vs Leg Extension Standards

How to read the table: The first number is Lying Leg Curl; the second is Leg Extension. Each number is the lowest estimated one-rep max needed to reach that strength level. Scroll horizontally on smaller screens.

BodyweightNoviceIntermediateAdvancedElite
100 lb
45.4 kg
22 / 29 lb
10 / 13.2 kg
37 / 46 lb
16.8 / 20.9 kg
56 / 69 lb
25.4 / 31.3 kg
76 / 89 lb
34.5 / 40.4 kg
110 lb
49.9 kg
24 / 31 lb
10.9 / 14.1 kg
39 / 49 lb
17.7 / 22.2 kg
60 / 73 lb
27.2 / 33.1 kg
81 / 95 lb
36.7 / 43.1 kg
120 lb
54.4 kg
25 / 33 lb
11.3 / 15 kg
41 / 52 lb
18.6 / 23.6 kg
64 / 78 lb
29 / 35.4 kg
85 / 101 lb
38.6 / 45.8 kg
130 lb
59 kg
26 / 35 lb
11.8 / 15.9 kg
44 / 55 lb
20 / 24.9 kg
67 / 82 lb
30.4 / 37.2 kg
90 / 106 lb
40.8 / 48.1 kg
140 lb
63.5 kg
28 / 36 lb
12.7 / 16.3 kg
46 / 57 lb
20.9 / 25.9 kg
71 / 86 lb
32.2 / 39 kg
95 / 112 lb
43.1 / 50.8 kg
150 lb
68 kg
29 / 38 lb
13.2 / 17.2 kg
48 / 60 lb
21.8 / 27.2 kg
74 / 90 lb
33.6 / 40.8 kg
99 / 117 lb
44.9 / 53.1 kg
160 lb
72.6 kg
30 / 40 lb
13.6 / 18.1 kg
50 / 63 lb
22.7 / 28.6 kg
77 / 94 lb
34.9 / 42.6 kg
103 / 122 lb
46.7 / 55.3 kg
170 lb
77.1 kg
32 / 41 lb
14.5 / 18.6 kg
52 / 65 lb
23.6 / 29.5 kg
80 / 98 lb
36.3 / 44.5 kg
108 / 127 lb
49 / 57.6 kg
180 lb
81.6 kg
33 / 43 lb
15 / 19.5 kg
54 / 68 lb
24.5 / 30.8 kg
84 / 102 lb
38.1 / 46.3 kg
112 / 132 lb
50.8 / 59.9 kg
190 lb
86.2 kg
34 / 44 lb
15.4 / 20 kg
56 / 70 lb
25.4 / 31.8 kg
87 / 105 lb
39.5 / 47.6 kg
116 / 137 lb
52.6 / 62.1 kg
200 lb
90.7 kg
35 / 46 lb
15.9 / 20.9 kg
58 / 73 lb
26.3 / 33.1 kg
90 / 109 lb
40.8 / 49.4 kg
120 / 142 lb
54.4 / 64.4 kg
210 lb
95.3 kg
36 / 48 lb
16.3 / 21.8 kg
60 / 75 lb
27.2 / 34 kg
93 / 113 lb
42.2 / 51.3 kg
124 / 146 lb
56.2 / 66.2 kg
220 lb
99.8 kg
37 / 49 lb
16.8 / 22.2 kg
62 / 77 lb
28.1 / 34.9 kg
96 / 116 lb
43.5 / 52.6 kg
128 / 151 lb
58.1 / 68.5 kg
230 lb
104.3 kg
39 / 51 lb
17.7 / 23.1 kg
64 / 80 lb
29 / 36.3 kg
98 / 120 lb
44.5 / 54.4 kg
132 / 156 lb
59.9 / 70.8 kg
240 lb
108.9 kg
40 / 52 lb
18.1 / 23.6 kg
66 / 82 lb
29.9 / 37.2 kg
101 / 123 lb
45.8 / 55.8 kg
135 / 160 lb
61.2 / 72.6 kg

How Your Lying Leg Curl vs Leg Extension 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 lying leg curl strength level

The standards use the sex-specific targets from the individual Lying Leg 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 heavier lifters are expected to lift more without requiring strength to increase pound for pound.

3. 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.

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.

StageWhat happens
Estimate each maxUse the entered weight for 1 rep; for 2–12 reps, keep the lower formula result.
Rate the lying leg curlAdjust lying leg curl targets to exact bodyweight with the two-thirds rule.
Rate the leg extensionAdjust leg extension targets to exact bodyweight with the two-thirds rule.
Compare different levelsName the lower-level lift as the priority.
Compare matching levelsUse 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 Lying Leg Curl and Leg Extension 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 leg extension standard is higher; below zero means the lying leg curl 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:

Novice closest match120 lb

The standards come closest at 120 lb.

Leg Extension target is higher4 strength levels

Novice, Intermediate, Advanced, and Elite at every displayed bodyweight.

Elite difference25 → 46 lb

11.4 → 20.9 kg from 120 to 300 lb bodyweight.

How men’s lying leg curl and leg extension standards differ by bodyweightFour colored lines show the difference in pounds between the leg extension and lying leg curl standards at Novice, Intermediate, Advanced, and Elite. Zero means the two standards are equal. Above zero means the leg extension standard is higher. Below zero means the lying leg curl standard is higher.NoviceIntermediateAdvancedElite0+10+20+30+40+50120140160180200220240260280300Bodyweight (lb)Difference between standards (lb)

How to read the table: Every number is the leg extension standard minus the lying leg curl standard. A plus sign means the leg extension standard is higher. A minus sign means the lying leg curl standard is higher.

BodyweightNoviceIntermediateAdvancedElite
120 lb
54.4 kg
+13 lb
+5.9 kg
+17 lb
+7.7 kg
+19 lb
+8.6 kg
+25 lb
+11.4 kg
130 lb
59 kg
+14 lb
+6.4 kg
+18 lb
+8.2 kg
+20 lb
+9.1 kg
+27 lb
+12.3 kg
140 lb
63.5 kg
+15 lb
+6.8 kg
+19 lb
+8.6 kg
+21 lb
+9.5 kg
+27 lb
+12.3 kg
150 lb
68 kg
+15 lb
+6.8 kg
+20 lb
+9 kg
+22 lb
+10 kg
+29 lb
+13.2 kg
160 lb
72.6 kg
+16 lb
+7.2 kg
+21 lb
+9.5 kg
+23 lb
+10.5 kg
+30 lb
+13.6 kg
170 lb
77.1 kg
+17 lb
+7.7 kg
+21 lb
+9.5 kg
+24 lb
+10.8 kg
+31 lb
+14 kg
180 lb
81.6 kg
+18 lb
+8.2 kg
+22 lb
+10 kg
+25 lb
+11.4 kg
+33 lb
+14.9 kg
190 lb
86.2 kg
+18 lb
+8.2 kg
+23 lb
+10.4 kg
+26 lb
+11.8 kg
+34 lb
+15.4 kg
200 lb
90.7 kg
+18 lb
+8.2 kg
+24 lb
+10.8 kg
+27 lb
+12.2 kg
+35 lb
+15.9 kg
210 lb
95.3 kg
+20 lb
+9.1 kg
+24 lb
+10.9 kg
+28 lb
+12.7 kg
+36 lb
+16.3 kg
220 lb
99.8 kg
+20 lb
+9.1 kg
+26 lb
+11.8 kg
+28 lb
+12.7 kg
+38 lb
+17.3 kg
230 lb
104.3 kg
+20 lb
+9.1 kg
+26 lb
+11.8 kg
+29 lb
+13.2 kg
+38 lb
+17.2 kg
240 lb
108.9 kg
+21 lb
+9.5 kg
+27 lb
+12.3 kg
+30 lb
+13.6 kg
+40 lb
+18.2 kg
250 lb
113.4 kg
+21 lb
+9.5 kg
+28 lb
+12.7 kg
+32 lb
+14.5 kg
+41 lb
+18.6 kg
260 lb
117.9 kg
+23 lb
+10.4 kg
+28 lb
+12.7 kg
+32 lb
+14.6 kg
+42 lb
+19 kg
270 lb
122.5 kg
+23 lb
+10.5 kg
+29 lb
+13.1 kg
+33 lb
+14.9 kg
+43 lb
+19.5 kg
280 lb
127 kg
+24 lb
+10.9 kg
+30 lb
+13.6 kg
+34 lb
+15.4 kg
+44 lb
+20 kg
290 lb
131.5 kg
+24 lb
+10.9 kg
+30 lb
+13.6 kg
+34 lb
+15.4 kg
+45 lb
+20.4 kg
300 lb
136.1 kg
+25 lb
+11.4 kg
+31 lb
+14.1 kg
+36 lb
+16.4 kg
+46 lb
+20.9 kg

How Women’s Lying Leg Curl and Leg Extension Standards Differ

What the women’s data shows:

Novice closest match100 lb

The standards come closest at 100 lb.

Leg Extension target is higher4 strength levels

Novice, Intermediate, Advanced, and Elite at every displayed bodyweight.

Elite difference13 → 25 lb

5.9 → 11.4 kg from 100 to 240 lb bodyweight.

How women’s lying leg curl and leg extension standards differ by bodyweightFour colored lines show the difference in pounds between the leg extension and lying leg curl standards at Novice, Intermediate, Advanced, and Elite. Zero means the two standards are equal. Above zero means the leg extension standard is higher. Below zero means the lying leg curl standard is higher.NoviceIntermediateAdvancedElite0+5+10+15+20+25100120140160180200220240Bodyweight (lb)Difference between standards (lb)

How to read the table: Every number is the leg extension standard minus the lying leg curl standard. A plus sign means the leg extension standard is higher. A minus sign means the lying leg curl standard is higher.

BodyweightNoviceIntermediateAdvancedElite
100 lb
45.4 kg
+7 lb
+3.2 kg
+9 lb
+4.1 kg
+13 lb
+5.9 kg
+13 lb
+5.9 kg
110 lb
49.9 kg
+7 lb
+3.2 kg
+10 lb
+4.5 kg
+13 lb
+5.9 kg
+14 lb
+6.4 kg
120 lb
54.4 kg
+8 lb
+3.7 kg
+11 lb
+5 kg
+14 lb
+6.4 kg
+16 lb
+7.2 kg
130 lb
59 kg
+9 lb
+4.1 kg
+11 lb
+4.9 kg
+15 lb
+6.8 kg
+16 lb
+7.3 kg
140 lb
63.5 kg
+8 lb
+3.6 kg
+11 lb
+5 kg
+15 lb
+6.8 kg
+17 lb
+7.7 kg
150 lb
68 kg
+9 lb
+4 kg
+12 lb
+5.4 kg
+16 lb
+7.2 kg
+18 lb
+8.2 kg
160 lb
72.6 kg
+10 lb
+4.5 kg
+13 lb
+5.9 kg
+17 lb
+7.7 kg
+19 lb
+8.6 kg
170 lb
77.1 kg
+9 lb
+4.1 kg
+13 lb
+5.9 kg
+18 lb
+8.2 kg
+19 lb
+8.6 kg
180 lb
81.6 kg
+10 lb
+4.5 kg
+14 lb
+6.3 kg
+18 lb
+8.2 kg
+20 lb
+9.1 kg
190 lb
86.2 kg
+10 lb
+4.6 kg
+14 lb
+6.4 kg
+18 lb
+8.1 kg
+21 lb
+9.5 kg
200 lb
90.7 kg
+11 lb
+5 kg
+15 lb
+6.8 kg
+19 lb
+8.6 kg
+22 lb
+10 kg
210 lb
95.3 kg
+12 lb
+5.5 kg
+15 lb
+6.8 kg
+20 lb
+9.1 kg
+22 lb
+10 kg
220 lb
99.8 kg
+12 lb
+5.4 kg
+15 lb
+6.8 kg
+20 lb
+9.1 kg
+23 lb
+10.4 kg
230 lb
104.3 kg
+12 lb
+5.4 kg
+16 lb
+7.3 kg
+22 lb
+9.9 kg
+24 lb
+10.9 kg
240 lb
108.9 kg
+12 lb
+5.5 kg
+16 lb
+7.3 kg
+22 lb
+10 kg
+25 lb
+11.4 kg

Lying Leg Curl and Leg Extension Exercises Used by This Calculator

This calculator uses a strict lying leg curl and a bilateral machine leg extension. Use strict canonical Lying Leg Curl and Leg Extension tests. Do not mix variations, assistance, partial range, momentum, or different load conventions.

Use a strict, repeatable Lying 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 prone bilateral machine leg curl Hip contact and lower-leg pad stay consistent Back, hips, pelvis, thighs, body pad, and pad position stay stable Enter displayed machine or stack weight. Keep the same equipment and setup when retesting.

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.

Enter one recent Lying Leg Curl result and one recent Leg Extension result

Enter the canonical working weight and a whole number of strict repetitions for each exercise. Pounds and kilograms can be mixed.

  • Lying Leg Curl — View the individual Lying Leg Curl standards and next strength-level target.
  • Leg Extension — View the individual Leg Extension 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.
  • 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.
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