Weight for reps calculator (rep max chart)
It helps you pick a working weight when your program calls for a set number of reps.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter one rep max (kg or lb) and target reps.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Inverse Epley: weight = 1RM ÷ (1 + reps ÷ 30). Inverse Brzycki: weight = 1RM × (37 − reps) ÷ 36. One rep = 1RM.
Example
Inputs: One rep max (kg or lb) = 120, Target reps = 5. Result: Suggested weight (average): 104.8; By Epley: 102.9; By Brzycki: 106.7.
Limits and caveats
- Weights are estimates; your real capacity depends on fatigue, sleep and technique.
- Round to the nearest plates available in your gym.
Questions about this tool
How much should I lift for 10 reps with a 100 kg max?
About 75 kg, or 75% of your max, and both formulas agree on that.
What percentage of 1RM is a 5 rep weight?
Roughly 87% using the average of the two formulas.
Why does the chart stop at 12 reps?
The formulas lose accuracy at high reps, so results beyond that are not reliable.