Precis

1RM Calculator

Epley formula, from any set you actually completed. Saving a lift here sets your training max for the overload scheme and RPE calculator.

  • Instant results
  • Private: runs in your browser
  • Free, no sign-up
Most accurate under ~10 reps. This writes to your training-max profile as soon as you change a value.
Estimated 1-rep max
0 kg
saving as your Squat max

How accurate is the Epley 1RM formula?

The Epley formula estimates your true one-rep max from any set you can complete for up to about 10 reps, using weight × (1 + reps ÷ 30). It's an estimate, not a guarantee — accuracy drops the higher your rep count goes, and factors like bar speed, fatigue and technique on the day all shift the real number slightly. It's still the most widely used method for programming percentage-based training, which is exactly what feeds the Progressive Overload Calculator and RPE Calculator on this site.

Frequently asked questions

What's the difference between Epley and Brzycki formulas?

Both estimate 1RM from a sub-max set using slightly different formulas — Epley tends to estimate slightly higher at higher rep counts, Brzycki slightly lower. They typically agree closely under 5 reps.

How many reps should I use to estimate my 1RM?

Lower rep sets (1–5) give the most accurate estimate. Above about 8–10 reps, formula-based estimates get progressively less reliable.

Should I actually test my true 1RM?

Not necessary for most training — a formula estimate from a recent heavy set is accurate enough to program percentages from, and it's safer than maxing out regularly.

Related searches

RPE CalculatorConvert an RPE + reps combination into %1RM and working weight. Training Percentage Calculator50% to 100% of your max, rounded to plate-loadable weights. Progressive OverloadA 4-week 5/3/1-style percentage scheme built from your training max.