How an e1RM is worked out
An estimate starts from a set: a weight and the number of reps you completed. Because a heavier weight allows fewer reps, that pair of numbers implies a ceiling for a single. Several published formulas turn the pair into an estimate. One Fitness Hub averages three of them, Mayhew, Wathan and Lombardi, which stay reasonable across a wide range of rep counts. The simpler Epley and Brzycki formulas drift once a set goes past about 15 reps. A set of one rep is recorded as the weight itself.
A worked example
A set of 225 lb for 5 reps comes to an e1RM of 264.8 lb. A set of 185 lb for 8 reps comes to 232.5 lb. At the same weight, more reps give a higher estimate, which is why a new rep record at a familiar weight moves the number even when you never touch a heavier bar.
What an estimate can and cannot tell you
An e1RM is a way to compare sets on one scale and to see a trend, not a promise that you can lift that weight today. Sets taken close to failure, with steady form and similar rest, give the most useful numbers. Very long sets and sets with changing technique are noisier. Treat the figure as a fitness estimate, never as a measured or verified max.
Bodyweight movements
For calisthenics the app works from the effective load (bodyweight times a movement factor, plus any added weight, minus assistance) and a separate blend of the Epley and Lombardi multipliers, for sets of one to ten reps.
In One Fitness Hub
- The Log shows a live e1RM as you enter a set, and an exercise's page opens with today's best e1RM and Show as chips from 1RM to 10RM.
- A new best e1RM from two or more reps earns an estimated PR, drawn dashed as "PR · Est.". A heavier single is an actual PR.
- A set marked to failure scores only the reps before the failed one.
- The one rep max calculator on this site uses the same formula, so a number from either place agrees.
Common questions
Is an e1RM the same as a 1RM?
No. A 1RM is a weight you actually lifted once. An e1RM is an estimate from a set of several reps, so it can sit above or below a real single on the day.
Which formula does One Fitness Hub use?
It averages the Mayhew, Wathan and Lombardi formulas for strength lifts and uses a separate Epley and Lombardi blend for bodyweight movements.
Which sets give the steadiest estimate?
Lower-rep sets tend to give steadier estimates than long sets of 15 or more, where every formula loses accuracy.
Related terms
- PR (personal record): A PR, or personal record, is your best result so far on a particular lift, cardio effort or workout.
- 1000 lb total: The 1000 lb total is the combined best one-rep max of your barbell squat, bench press and deadlift, and the 1000 pound club recognises totals of 1,000 lb (453.6 kg) or more.
- Relative strength: Relative strength is how much you lift compared with how much you weigh, usually shown as a ratio such as 1.5 times bodyweight.
- Failure reps: Training to failure means continuing a set until you cannot complete another repetition with good form; the failure rep is the attempt you could not finish.
- Volume load: Volume load is the total weight you moved: for each set, multiply the reps by the weight, then add up the sets.
Keep reading
General education and fitness estimates, not medical or dietary advice. Figures from the app are informational and are not reviewed by a certified personal trainer.