One-rep max calculator · 1RM estimate
Purpose
Use this calculator to estimate how much your client could lift once, without a maximal attempt. Your client lifts a weight until they cannot do another good repetition. The calculator turns that set into an estimate.
Each formula was built on a different group of lifters, so they give slightly different answers. SOLO routing uses the formula SOLO uses for the exercise's movement. The average takes the mean of all five.
How to measure
- Preparation
- Warm up with the exercise you will test. Choose a weight your client can lift 10 times or fewer with good technique.
- Equipment
- The exercise's usual equipment, plus a spotter for free weights
Warm up
Do a few light sets of the same exercise, adding weight each time.
Lift to fatigue
Your client lifts the chosen weight until they cannot complete another repetition with good technique.
Enter the set
Search for the exercise, then enter the weight and the number of completed repetitions.
Stop the set when technique breaks down or your client feels pain.
Scoring
Count only repetitions completed through the full range. Use sets of 1 to 10 repetitions.
Formulas
- Epley
- weight × (1 + repetitions ÷ 30)
- Brzycki
- weight × 36 ÷ (37 − repetitions)
- Mayhew
- 100 × weight ÷ (52.2 + 41.9 × e^(−0.055 × repetitions))
- Lombardi
- weight × repetitions^0.10
- O'Conner
- weight × (1 + repetitions ÷ 40)
- Average of 5 formulas
- the mean of the five estimates above
- SOLO routing
- Mayhew for pushes, Brzycki for squats, Epley for hinges, and the average for every other movement
An estimate is never lower than the weight lifted. Training loads round to 2.5 kg. Pounds convert to kilograms before the calculation.
Interpretation
This is an estimate, not a tested maximum. Compare results for the same exercise and formula.
Sources
- LeSuer et al.: accuracy of prediction equations for estimating 1-RM (1997)Journal of Strength and Conditioning Research 11(4):211–213. Lists the Epley, Brzycki, Mayhew, Lombardi and O'Conner equations and supports sets of 10 repetitions or fewer.
- Mayhew et al.: prediction equations for 1RM bench press in women (2008)Journal of Strength and Conditioning Research 22(5):1570–1577. Lists the same equations with their original sources.
- Brzycki, M.: predicting a one-rep max from reps-to-fatigue (1993)Journal of Physical Education, Recreation and Dance 64(1):88–90.
Sources checked by SoloTrainer.net · 24 Sep