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Health & Fitness

One rep max calculator

Two ways in. Give it a set and it weighs six formulas by how well each one holds up at that rep range. Or give it the set plus how hard it felt, and it uses the RPE chart, which is more reliable than any formula because it knows something they do not: how close you were to failure.

RPE 8 means about two reps left.

Estimated 1RM

123.3kg

That set was

81.1%

of your max

In the tank

2reps

About 2 more reps left in the tank

This is the estimate to trust. A rep-only formula sees "5 reps" and has to guess how hard they were; telling it the set was RPE 8 removes exactly the thing it was guessing at. The chart comes from Reactive Training Systems, and it is self-consistent by construction here: RPE 9 for one rep and RPE 10 for two both mean one rep left, so both resolve to the same percentage.
What you should hit for reps
Reps% of maxWeight
1100%122.5 kg
295.5%117.5 kg
392.2%112.5 kg
489.2%110 kg
586.3%107.5 kg
683.7%102.5 kg
781.1%100 kg
878.6%97.5 kg
976.2%95 kg
1073.9%90 kg
1170.7%87.5 kg
1268%85 kg
What to programme from
IntensityUsed forWeight
95%Singles, peaking117.5 kg
90%Heavy doubles and triples110 kg
85%Strength work, sets of 3 to 5105 kg
80%Sets of 5, the bread and butter97.5 kg
75%Sets of 6 to 8, volume92.5 kg
70%Sets of 8 to 10, hypertrophy87.5 kg
65%Higher reps, technique work80 kg
60%Speed work and back-off sets75 kg
50%Warm-ups and deloads62.5 kg

Every weight is rounded to the nearest 2.5 kg, because that is the smallest jump a normal plate set can actually make.