One Rep Max Calculator – Estimate Maximum Lift

Estimate your 1-rep max (1RM) for any lift from a submaximal set using the Epley formula.

❤️ Health📐
Weight lifted (lbs)
Reps completed
Please enter valid values.

Formula & Reference

VariableFormulaUnits
One Rep Max Calculator – Estimate Maximum Liftresult

Step-by-Step Examples

Example 1
225 lbs × 5 reps

  • 1RM = 225 × (1 + 5/30) = 262.5 lbs
✓ ~263 lbs 1RM
Example 2
135 lbs × 10 reps

  • 1RM = 135 × 1.33 = 180 lbs
✓ ~180 lbs 1RM
Example 3
315 lbs × 3 reps

  • 1RM = 315 × 1.10 = 347 lbs
✓ ~347 lbs 1RM

Real-World Applications

Common Mistakes to Avoid

⚠️
Attempting 1RM without experience

For most gym-goers, testing true 1RM is risky. Use this formula to estimate it safely.

⚠️
Using high-rep estimates

Above 10 reps, accuracy decreases. Best results with 3-8 rep sets.

Frequently Asked Questions

Formula accuracy?
Epley formula is within ±5% for 3-8 reps. Less accurate above 10 reps.
Good 1RM benchmarks?
Squat: BW×1.5 for intermediate. Bench: BW for males intermediate. Deadlift: BW×2 intermediate.
Percentage-based training?
65-75% 1RM for hypertrophy (8-12 reps). 80-90% for strength (3-6 reps). 90%+ for power (1-3 reps).

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