One-rep max calculator
Your 1RM from any set, and the loads for every percentage.
Your files stay on your device
This tool runs entirely in your browser. What you paste is processed on your device and is never sent to a server, so it is safe to use with tokens, keys and unpublished text.
Example
Example: 225 lb for 5 reps on the bench, and the loads it gives
A hard set of 5 reps at 225 lb on the bench press, with good form. Unit lb, formula Average of three.
- Epley: 225 × (1 + 5 ÷ 30) = 262.5 lb.
- Brzycki: 225 × 36 ÷ (37 − 5) = 253.1 lb.
- Lombardi: 225 × 5^0.10 = 264.3 lb. The average of the three, 260 lb, is the estimate.
| % of 1RM | Load | Reps |
|---|---|---|
| 100% | 260 lb | ≈ 1 |
| 90% | 234 lb | ≈ 4 |
| 85% | 221 lb | ≈ 6 |
| 80% | 208 lb | ≈ 8 |
| 75% | 195 lb | ≈ 10 |
| 70% | 182 lb | ≈ 12 |
| 60% | 156 lb | ≈ 18 |
| 50% | 130 lb | ≈ 25 |
Estimated 1RM: 260 lb. A programme that asks for sets of 8 at 80 % means 208 lb. Loads are rounded to the nearest pound.
How it works
- Enter a weight you lifted with good form and how many reps you did — 3 to 10 gives the best estimate.
- Keep the average of the three formulas or pick one.
- Read your estimated one-rep max and the table of loads from 100 % down to 50 %, with the reps you can expect at each.
Frequently asked questions
- How is the 1RM estimated?
- From the weight and reps of a hard set: Epley w × (1 + r/30), Brzycki w × 36/(37 − r) and Lombardi w × r^0.1. For 100 kg × 5 they give 116.7, 112.5 and 117.5 kg — about 115.5 kg on average.
- How many reps should I use?
- A set of 3–10 reps close to failure. Above 12 the estimate becomes unreliable, and one rep is simply your max.
- What is the percentage table for?
- Training programmes prescribe loads as a percentage of your 1RM: 80 % for sets of about 8, 70 % for about 12. Loads are rounded to 0.5 kg or 1 lb, as plates allow.
- Should I test my real max?
- Only warmed up, with good technique and a spotter or safety bars. The estimate lets you train without testing.
- How do I estimate a squat or deadlift max?
- The same way, from the weight and reps of a hard set: 315 lb squatted for 3 reps gives about 343.9 lb on average (Epley 346.5, Brzycki 333.5, Lombardi 351.6 lb). A single rep is simply your max.
- Why do the formulas disagree more at high reps?
- They part ways as the reps rise. At 225 lb × 5 they span 253.1 to 264.3 lb; at 185 lb × 15, Brzycki says 302.7 lb and Lombardi 242.5 lb. A set of 3 to 10 reps keeps them close.
- Is anything saved?
- No. It is worked out in your browser.