1RM & Strength Standards Calculator
Enter any set you've done - weight and reps - and see your estimated one-rep max. Compare your lifts to strength levels for your bodyweight, and plan your next training weights. Runs in your browser, nothing uploaded.
Learn more: 1RM estimation and strength training
How 1RM formulas work - from reps to single-rep max
A one-rep max (1RM) is the heaviest weight you can lift for a single repetition with good form. Rather than testing it directly, lifters estimate it from lighter weights lifted for multiple reps using mathematical formulas. The Epley formula (weight × (1 + reps/30)) and Brzycki formula (weight × (36 / (37 - reps))) are two common approaches. For example, if you lifted 100 kg for 5 reps, Epley estimates your 1RM at 100 × (1 + 5/30) = 116.7 kg. Estimates are most accurate when tested with 3-6 reps - accuracy drops significantly above 10 reps because heavier weights tested for many reps introduces too many variables (fatigue, technique breakdown).
Wilks and DOTS scores - comparing lifters of different bodyweights
Raw lift numbers only tell part of the story - a 150 kg squat means something different for a 60 kg lifter versus a 100 kg lifter. The Wilks coefficient and DOTS score both normalize your total lifted weight against your bodyweight using polynomial equations, so lifters of any size can be compared fairly on the same scale. Wilks is the older standard (requires a total of squat + bench + deadlift). DOTS is newer and considered more accurate across a wider range of bodyweights. A Wilks score above 400 is competitive at the elite level in powerlifting.
FAQ
Why do different formulas give different 1RM estimates?
Each formula models rep-to-max conversion slightly differently - some assume fatigue increases exponentially, others linearly. Testing with 3-6 reps minimizes the variation between formulas. Above 10 reps, the differences widen. This calculator averages all 6 formulas to reduce noise.
Is it safe to test my actual 1RM?
Testing true 1RM is risky without proper setup, a spotter, and good technique. Estimating from a 3-5 rep set is safer and equally valid for training planning. Always warm up thoroughly and stop if form breaks down.
Can I use this calculator for bodyweight exercises like pullups and dips?
Yes - enter your bodyweight plus any additional weight (belt or added weight). The formulas work the same way. For unweighted pullups, the "weight" is simply your bodyweight.