One Rep Max (1RM) calculator

Enter how many reps you can do with some weight

This would be your weight for 1RM

=?

Other Rep Maxes

1RM Percentages

  • 2RM: 96%
  • 3RM: 92%
  • 4RM: 89%
  • 5RM: 87%
  • 6RM: 84%
  • 7RM: 81%
  • 8RM: 79%
  • 9RM: 76%
  • 10RM: 73%
  • 11RM: 71%
  • 12RM: 68%

Convert TM percentages into RM percentages

Enter what percentage of RM your TM is

  • 100% TM = 90.0% 1RM
  • 97.5% TM = 88.0% 1RM
  • 95% TM = 85.5% 1RM
  • 92.5% TM = 83.5% 1RM
  • 90% TM = 81.0% 1RM
  • 87.5% TM = 79.0% 1RM
  • 85% TM = 76.5% 1RM
  • 82.5% TM = 74.5% 1RM
  • 80% TM = 72.0% 1RM
  • 77.5% TM = 70.0% 1RM
  • 75% TM = 67.5% 1RM
  • 72.5% TM = 65.5% 1RM
  • 70% TM = 63.0% 1RM
  • 67.5% TM = 61.0% 1RM
  • 65% TM = 58.5% 1RM
  • 62.5% TM = 56.5% 1RM
  • 60% TM = 54.0% 1RM
  • 57.5% TM = 51.5% 1RM
  • 55% TM = 49.5% 1RM
  • 52.5% TM = 47.5% 1RM
  • 50% TM = 45.0% 1RM
  • 47.5% TM = 43.0% 1RM
  • 45% TM = 40.5% 1RM
  • 42.5% TM = 38.5% 1RM
  • 40% TM = 36.0% 1RM
  • 37.5% TM = 34.0% 1RM
  • 35% TM = 31.5% 1RM
  • 32.5% TM = 29.5% 1RM
  • 30% TM = 27.0% 1RM
  • 27.5% TM = 25.0% 1RM
  • 25% TM = 22.5% 1RM
  • 22.5% TM = 20.5% 1RM
  • 20% TM = 18.0% 1RM
  • 17.5% TM = 15.5% 1RM
  • 15% TM = 13.5% 1RM
  • 12.5% TM = 11.5% 1RM
  • 10% TM = 9.0% 1RM
  • 7.5% TM = 7.0% 1RM
  • 5% TM = 4.5% 1RM
  • 2.5% TM = 2.5% 1RM

What is a 1RM (One Rep Max)?

Your 1RM is the maximum weight you can lift for exactly 1 rep with proper form. It's a key number in strength training. Many percentage-based programs like The Rippler, 5/3/1, and others use your 1RM to calculate working weights.

How This Calculator Works

Enter a weight you've lifted and how many reps you did with it. The calculator uses RPE (Rate of Perceived Exertion) tables to estimate your 1RM. Unlike simple formula-based calculators (Epley, Brzycki), RPE tables account for effort level and are calibrated from trained strength athletes' data, making them more accurate, especially for higher rep ranges where simple formulas tend to diverge.

FAQ

How accurate are rep max calculators?

Calculators give a good estimate, but accuracy decreases as the rep difference grows. Estimating your 1RM from a 3-rep set is more reliable than from a 12-rep set. RPE-based calculations (used here) tend to be more accurate than simple formulas because they account for effort level.

What is RPE?

RPE stands for Rate of Perceived Exertion. It's a scale from 1-10 that measures how hard a set felt. RPE 10 means you couldn't do another rep. RPE 8 means you had about 2 reps left in the tank. If you're unsure of your RPE, leave it at 10.

Should I test my 1RM directly?

Testing a true 1RM is taxing on your body and carries injury risk, especially for beginners. Using a calculator to estimate from a lighter set (e.g. 3-5 reps) is safer and usually accurate enough for programming purposes.

What is a Training Max (TM)?

A Training Max is a percentage of your 1RM (typically 85-90%) used as the basis for calculating working weights in programs like 5/3/1. It builds in a buffer so you're not always training at your absolute max. Use the TM converter above to translate TM percentages into 1RM percentages.