1RM Calculator — One Rep Max
Estimate your one-rep max from a weight and rep count with three formulas, and get a 50–100% training load table in kg or lb.
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How to use
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Enter the weight lifted and the reps
Choose kg or lb
Check your estimated 1RM and the weight chart by percentage
How it works and good to know
Shows the average of the Epley, Brzycki and Lombardi formulas and each value. A single rep is simply the weight lifted. Reps from 1 to 20 are accepted, and above 10 you’re told accuracy drops. The chart runs from 50% to 100% in 5% steps, showing weights rounded down to plate increments (2.5 kg or 5 lb) with approximate reps. These are estimates; attempt a real max only with safety equipment and a spotter.