One Rep Max Calculator

Estimate your one rep max from a working set and use common percentages to set up training loads for strength work.

Weight lifted

Reps completed

Estimated 1RM

213.8 lb

Training percentages

95%

203.1 lb

90%

192.4 lb

85%

181.7 lb

80%

171.0 lb

75%

160.3 lb

70%

149.6 lb

60%

128.3 lb

How to Use

Enter the weight you lifted for a challenging set that still used solid form. The estimate is more useful when the source set reflects real effort without technique breakdown.
Enter the number of completed reps from that set. Lower rep counts usually produce more reliable one-rep-max estimates than very high-rep sets.
Review the estimated 1RM as a programming reference rather than a guarantee of what you can hit on a max-testing day. Sleep, fatigue, exercise selection, and experience all matter.
Use the training percentage table to pick working weights for volume, strength, or peaking phases without having to test an all-out single every week.
Recheck the estimate after a new rep PR or a stronger working set so your training percentages keep pace with your current strength level.

Frequently Asked Questions

What is one rep max?

One rep max is the maximum load you can lift for a single repetition with good form. It is commonly used as a reference point for strength programming and percentage-based training plans.

Do I need to actually test a max?

No. This calculator estimates 1RM from a lighter rep set, which is often safer, less fatiguing, and more practical for regular programming than testing an all-out single.

Why use multiple formulas?

Different rep-max equations can give slightly different answers, especially as reps get higher. Looking across formulas or using an average helps smooth out those differences and gives a more stable programming estimate.

Does this work for all lifts?

It works best for common barbell and dumbbell lifts where rep-based strength estimates are widely used, such as squat, bench press, deadlift, and overhead press. It is less dependable for highly technical or machine-specific movements.