The Bench Press Calculator estimates your one-repetition maximum (1RM) based on the weight you can bench press and the number of repetitions you complete. Your estimated 1RM is the predicted maximum weight you could lift for one repetition.
This calculator uses the Epley formula and supports both kilograms (kg) and pounds (lb). It can help you track strength progress and plan your bench press training without directly testing a maximal single lift.
Enter the weight you lifted, the number of repetitions you completed, and the weight unit.
The calculator does not convert the result into another unit. It reports the estimated 1RM using the same unit selected for the input weight.
Epley One-Repetition Maximum Formula
Estimated 1RM = Weight × (1 + Repetitions ÷ 30)
Where:
The calculation uses the numeric weight directly, so the output unit remains the same as the selected input unit.
Suppose you bench press 80 kg for 8 repetitions.
Step 1: Apply the Epley Formula
Estimated 1RM = 80 × (1 + 8 ÷ 30)
Estimated 1RM = 80 × (1 + 0.2667)
Estimated 1RM ≈ 80 × 1.2667
Estimated 1RM ≈ 101.33 kg
Based on this example, your estimated bench press one-repetition maximum is approximately 101.33 kg.
Pounds Example
If you bench press 175 lb for 5 repetitions:
Estimated 1RM = 175 × (1 + 5 ÷ 30)
Estimated 1RM ≈ 204.17 lb
The calculator keeps the result in the unit selected for the input weight.
The implementation applies weight×(1 + reps/30) without an exception for a single. At one repetition the multiplier is 31/30. That behavior is an extrapolation, not a correction to the weight actually lifted.
No. This bench page uses Epley, while the separate 1RM page uses a Brzycki-style denominator. Their predictions can differ for the same set because the mathematical relationships differ.
Yes. Choose lb and enter the complete set load in pounds. The predicted result stays in pounds. Do not enter a kilogram number while leaving the pound selector active.
The calculator cannot account for assistance. If a spotter contributed force, the listed load no longer represents what the lifter moved alone. Record that separately instead of treating it as an unassisted set.
It can support a comparison when the exercise standard and conditions are similar. Check the original load, repetitions and technique as well. A changed calculation method or easier movement standard can increase the estimate without the same change in strict performance.
These links provide starting points for reviewing relevant research and fitness guidance. The calculator's output is based specifically on the Epley equation implemented in its controller.
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