One-Rep-Max Calculator
Compare seven established one-rep-max formulas from a recent working set. Select the average for a balanced estimate, or choose the formula you prefer.
Your selected one-rep-max estimate
117 kg
Average of all formulas from 100 kg × 5 reps.
| Training focus | % of 1RM | Suggested weight |
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Formula comparison
Different formulas can produce slightly different results. The average is a useful default for most people; use a specific method if your coach or training plan calls for it.
| Formula | Estimated 1RM |
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Use the estimate wisely
One-rep-max formulas are estimates, not guarantees. They become less reliable as repetitions rise, especially above 10. Prioritise good technique, warm up properly, and use a spotter or safeties when appropriate.