Deadlift 1RM confidence interval
For a default example of 365 lb x 3, the seven formulas produce a practical confidence interval of 386.5 lb - 416.1 lb, with a formula mean of 399 lb.
Use this range as the answer, not a single number. If the set was clean and low-rep, the middle of the range is reasonable. If technique changed or reps were high, use the lower end and build a training max from there.
Suggested training range: about 330 to 380 lb, before rounding to plates and adjusting for recovery.
Scroll table horizontally
| Formula | Calculation | Estimate | Use it as |
|---|---|---|---|
| Epley | 365 x (1 + 3 / 30) | 401.5 lb | Optimistic side of the range |
| Brzycki | 365 x 36 / (37 - 3) | 386.5 lb | Conservative side of the range |
| Lombardi | 365 x 3^0.10 | 407.4 lb | Optimistic side of the range |
| O'Conner | 365 x (1 + 0.025 x 3) | 392.4 lb | Conservative side of the range |
| Mayhew | 100 x 365 / (52.2 + 41.9 x e^(-0.055 x 3)) | 416.1 lb | Optimistic side of the range |
| Wathan | 100 x 365 / (48.8 + 53.8 x e^(-0.075 x 3)) | 397.8 lb | Conservative side of the range |
| Lander | 100 x 365 / (101.3 - 2.67123 x 3) | 391.3 lb | Conservative side of the range |