All calculators

One rep max

Epley and Brzycki, both, because the guide publishes both and they disagree by a few kilograms. The percentage chart underneath turns the answer into working weights.

Estimated one rep max

Example

Epley

116.7kg

Brzycki

112.5kg

The two formulas differ by 4.2 kg here. That gap is the honest size of the error bar at this rep count, and it grows with reps. The guide says consistency matters more than which one you pick: use the same one every time and the trend is what you read.

Working weights

Reps%EpleyBrzycki
1100%116.7112.5
295%110.9106.9
393%108.5104.6
490%105101.3
587%101.597.9
685%99.295.6
880%93.490
1075%87.584.4
1270%81.778.8
1565%75.973.1

The percentages are the guide's chart, multiplied against the estimates above. Nothing here is gated: this table is the same for everybody.

10 or fewer

Save the set, not the estimate.

Your 100 kg x 5 can go on your records, where your dashboard, your progress page and your profile read it. The estimate itself is not stored: it moves every time you lift.

Signing up takes a minute to set up. This page will remember your numbers. Your numbers stay on this page either way.

Read how this is worked out