Use our one rep max calculator to find your estimated 1RM for any lift. This is the calculator we use in our 7/5/3 program to find our 50–80% training loads for the squat, bench press, deadlift, and overhead press.
Enter the weight you lifted and the number of reps you completed — for the most accurate estimate, use a recent set you took close to failure.
What is a one-rep max (1RM)?
Your one-rep max is the heaviest weight you can lift for a single, full repetition of an exercise with good form. It’s the standard way coaches measure strength on the big lifts — the squat, bench press, deadlift, and overhead press. You rarely need to test a true 1RM, though. Instead, you can estimate it from a hard set you’ve already done, which is exactly what this tool does.
How to use this calculator
- Enter the weight you lifted, in pounds.
- Enter the number of clean reps you completed before your form broke down.
- Press Calculate 1RM.
You’ll get your estimated one-rep max plus a full table of percentage-based training loads. Estimates are most accurate at lower rep ranges (roughly 2–8 reps), so a heavy set of 5 predicts your max far better than a set of 20.
Why your 1RM matters
Knowing your estimated max is what makes structured strength training possible. Instead of guessing, you can program each lift as a percentage of your 1RM and progress it deliberately, week to week. In our 7/5/3 program we train in the 50–80% range (highlighted in the results table) to build strength and muscle while managing fatigue — which matters even more after 40, when recovery windows are narrower.
A calculator is a starting point, not a coach. If you’d like help testing your lifts safely and building a plan around your numbers, book a consultation with Kathy, or read why structured programs beat random workouts.
Estimated 1RM
lbs
Percentage-based training loads
| % | Weight (lbs) |
|---|
Estimates use the Epley formula and are most accurate at lower rep ranges. Highlighted rows are the 50–80% range we program in 7/5/3.