One-Rep Max Calculator
Estimate your one-rep max (1RM) from a weight and rep count. Kova uses the Epley and Brzycki formulas and averages them, then builds a percentage table for your working sets.
Estimated one-rep max
212lb
Epley 216 lb · Brzycki 208 lb
Percentage of your 1RM
| Percentage | Weight (lb) | Approx. reps |
|---|---|---|
| 100% | 212 | 1 |
| 95% | 201 | 2 |
| 90% | 191 | 3 |
| 85% | 180 | 5 |
| 80% | 170 | 8 |
| 75% | 159 | 10 |
| 70% | 148 | 13 |
| 65% | 138 | 16 |
| 60% | 127 | 20 |
Reps are an approximation from the Epley formula. How many reps you can complete at a percentage varies by lift and training background, so treat the column as a planning guide and let your logged sets confirm it.
How this tool works
Epley estimates a one-rep max as weight × (1 + reps ÷ 30). Brzycki estimates it as weight × 36 ÷ (37 − reps). Kova shows both and uses their average, rounded to a whole unit, for the headline number and the percentage table. The approximate reps column inverts the Epley formula (reps ≈ 30 × (100 ÷ percent − 1)); it is a planning guide, because rep ability at a given percentage varies by lift and training background. Sets above 15 reps are not accepted because both formulas lose accuracy at high reps.
Worked example
185 lb for 5 clean reps gives an Epley estimate of 216 lb, a Brzycki estimate of 208 lb, and an average of 212 lb. The table then lists 170 lb at 80% for roughly 8 reps and 191 lb at 90% for roughly 3 reps.
When to use this tool
- Estimating strength from a hard set without testing a true max
- Choosing percentage-based working weights for strength or hypertrophy blocks
- Comparing progress across training cycles when rep ranges change
How to use the result
A one-rep max estimate is most useful as a programming reference, not a promise that you can lift that exact number today. Kova shows the Epley estimate, the Brzycki estimate, and an average of the two. Sets of one to ten clean reps tend to produce better estimates than very high-rep sets. Use the percentage table to choose training loads, then let actual bar speed, form, and recovery guide the final decision.
Training notes
- Base the estimate on a set with solid form and no missed reps.
- Retest from comparable rep ranges so week-to-week changes are meaningful.
- Round training weights to plates you can actually load and track the rounded number.
How to use one-rep max calculator
- 1
Enter your set
Type the weight you lifted and the number of clean reps you completed.
- 2
Read your estimate
See your estimated one-rep max from both the Epley and Brzycki formulas.
- 3
Program your sets
Use the percentage table to pick loads for your working sets.
Keep planning your workout
Put your plan into practice
Kova helps you log your workouts, follow a program, and keep your next targets in view.
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