One Rep Max (1RM) Calculator
Estimate your 1RM from any set — then see how it grades, Beginner to Elite, against real competition data.
Percent of 1RM by reps (Epley)
| Set | Intensity (% of 1RM) | Example at 225 lb 1RM (lb) | Example (kg) |
|---|---|---|---|
| 1 reps | 97% of 1RM | 218 lb | 99 kg |
| 2 reps | 94% of 1RM | 211 lb | 96 kg |
| 3 reps | 91% of 1RM | 205 lb | 93 kg |
| 4 reps | 88% of 1RM | 199 lb | 90 kg |
| 5 reps | 86% of 1RM | 193 lb | 87 kg |
| 6 reps | 83% of 1RM | 188 lb | 85 kg |
| 8 reps | 79% of 1RM | 178 lb | 81 kg |
| 10 reps | 75% of 1RM | 169 lb | 77 kg |
| 12 reps | 71% of 1RM | 161 lb | 73 kg |
| 15 reps | 67% of 1RM | 150 lb | 68 kg |
FAQ
How is one-rep max calculated from reps?
Strenf uses the Epley formula: 1RM = weight × (1 + reps ÷ 30). A 225 lb set of 5 estimates a 263 lb single. Estimates are most accurate under 10 reps.
Do I have to actually test my 1RM?
No — submaximal estimates from a hard set of 3–8 reps are safer and nearly as accurate for programming and grading purposes.
What's a good 1RM?
It depends on the lift, your sex, bodyweight and age. Use the grading option here, or see the full standards tables — graded Beginner to Elite against competition data.
How accurate is an estimated one-rep max?
Accurate enough to program with, not accurate enough to argue about. Every rep-based formula assumes a typical relationship between reps and load, and real lifters vary — two people who both press 225 for 5 may not both single the same weight. The estimate drifts upward as reps climb, so a set of 3 to 5 gives a closer figure than a set of 15.
Why does Strenf use the Epley formula?
It is the simplest of the common estimators and it matches what the rest of the site grades against, so the number here and the number in the app are the same number. Other formulas exist and disagree slightly, particularly above 10 reps.
Should I convert to kilograms?
Strenf publishes pounds first because most of its readers train in pounds, but every standards table on the site also ships a kilogram version, and the table above lists both. One pound is 0.45359237 kilograms.
Full standards
Bench Press standards · Back Squat standards · Deadlift standards · Overhead Press standards · all lifts