Simply type in the maximum you can lift for a certain amount of reps and the calculator will predict your 1RM, your 1-Rep Max along with your 3RM, 6RM, 10RM and 12RM.
There are multiple formulas for predicting 1RM, so this calculator could vary slightly with other ones, since the formula used may differ. This calculator uses the Brzycki 1RM Formula ( 1RM = W x (36 / (37 – R)) ).
Here are some different formulas for calculating 1-Rep Max:
- Brzycki: 1RM = W x (36 / (37 – R))
- Wathan: 1RM = (100 x W) / (48.8 + (53.8 x e-0.075 x R))
- Lander: 1RM = (100 x W) / (101.3 – 2.67123 x R)
- Epley: 1RM = W x (1 + 0.0333 x R)
- Lombardi: 1RM = W x R0.1
- Mayhew et al.: 1RM = (100 x W) / (52.2 + (41.9 x e-0.055 x R))
- O’Conner et al.: 1RM = W x (1 + 0.025 x R)