What this calculator does
Bench press one-rep max works out estimated one-rep max (1RM) bench press from a weight and rep count, using the Epley formula. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formula1RM = weight × (1 + reps/30)
The inputs explained
| Field | What to enter |
|---|---|
| Weight lifted (kg) | A number, measured in kg. Starts at 80. |
| Reps performed | A number. Starts at 8. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with weight lifted
Every other input is held at the calculator’s starting values while weight lifted varies. Select any row to load that scenario into the calculator.
How the answer changes with weight lifted
| Weight lifted (kg) | Estimated one-rep max | Note |
|---|---|---|
| 40 | 50.7 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |
| 60 | 76.0 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |
| 80 | 101.3 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |
| 120 | 152.0 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |
| 160 | 202.7 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |
| 240 | 304.0 kg | Epley formula estimate; accuracy drops for very high (>12) rep counts |