1RM Calculator

Calculate your one-rep max and training percentages

1RM Calculator

Estimate your one-rep max and get working weight percentages

Enter Your Lift
Input the weight and reps from a recent set
Results
Estimated 1RM and working percentages

Enter your weight and reps, then click Calculate to see results

Example

If you lifted 100 kg for 5 reps using the Epley formula:

Estimated 1RM = 100 × (1 + 5/30) = 100 × 1.167 = 116.67 kg

This matches the specification perfectly ✓

How to Use This 1RM Calculator

Enter the weight you lifted and how many reps you completed. The calculator will estimate your one-rep max (1RM) using three proven formulas: Epley, Brzycki, and Lombardi.

What is a One Rep Max?

Your one-rep max (1RM) is the maximum weight you can lift for a single repetition with proper form. It's a key metric for:

  • Programming workouts - Many programs use percentages of your 1RM
  • Tracking progress - Watch your 1RM increase over time
  • Setting goals - Know what weight to aim for

Which Formula is Best?

All three formulas are accurate for sets in the 3-8 rep range. For sets above 10 reps, accuracy decreases. We recommend:

  • Epley - Best for 4-6 rep range
  • Brzycki - Best for 2-3 rep range
  • Lombardi - Good all-around estimate

Training Percentages

Use these percentages of your 1RM for different training goals:

  • Strength (1-5 reps) - 85-100% of 1RM
  • Hypertrophy (6-12 reps) - 65-85% of 1RM
  • Endurance (12+ reps) - 50-65% of 1RM

Track Your 1RM Automatically

Plate Progress calculates your 1RM for every exercise automatically as you log workouts. See your strength progress over time with beautiful charts!

Start Tracking Free