Which 1RM Formula Should You Use?
There are 7 scientifically-validated formulas for calculating one rep max (1RM). Each has its strengths and is best suited for different types of lifters and training goals. Our deadlift calculator uses all of them and provides an average for maximum accuracy.
Our Recommendation
For most people: Use the average of all formulas or stick with Epley (most popular).
For beginners: Try Brzycki for conservative estimates.
For accuracy: Compare multiple formulas and use your training history to decide.
Formula Comparison
| Formula | Equation | Best For | Details |
|---|---|---|---|
| Epley | Weight × (1 + Reps÷30) | Most popular, general use | Learn More |
| Brzycki | Weight × (36÷(37-Reps)) | Beginners, conservative | Learn More |
| Lander | (100×Weight)÷(101.3-2.67123×Reps) | Olympic weightlifting | Learn More |
| Lombardi | Weight × Reps^0.10 | Powerlifters, strongmen | Learn More |
| Mayhew et al. | (100×Weight)÷(52.2+41.9×e^(-0.055×Reps)) | Higher rep ranges | Learn More |
| O'Conner | Weight × (1 + Reps÷40) | Similar to Epley | Learn More |
| Wathan | (100×Weight)÷(48.8+53.8×e^(-0.075×Reps)) | Research-based | Learn More |
Formula Comparison Example
If you can deadlift 315 lbs (143 kg) for 5 reps, here's what each formula predicts for your 1RM:
Results in Pounds
Results in Kilograms
Note: These are estimates only. Individual results may vary based on training experience, technique, and other factors. Always prioritize proper form and safety when training.
Ready to Calculate Your Deadlift Max?
Use our calculator that includes all these formulas plus training percentages and more.
Try Our Deadlift Calculator