One Rep Max Calculator

Estimate your one rep max from the weight you lifted and the number of reps completed. This free one rep max calculator includes common strength formulas, projected rep tables, and percentage-based training weights in a clean calculator layout.

Calculate One Rep Max

One rep max is estimated from weight lifted and reps completed using common strength formulas.
Training weights are shown as percentages of your known one rep max.
Your result will appear here.

How the one rep max calculator works

Estimate 1RM:
Uses your weight lifted and reps completed to estimate your maximum single rep.

Common formulas:
The calculator includes Epley, Brzycki, Lander, and Lombardi formulas.

Training weights:
It also shows common percentages like 60%, 70%, 80%, 90%, and more.

Rep planning:
You also get projected working weights for different rep ranges.

Why 1RM estimates matter

One rep max estimates can help lifters organize strength training without testing a true max every session. Many people use them for percentage-based programming, progress tracking, and working set planning.

They are especially useful when you want a practical training reference from a normal work set.

What your result means

Your result shows an estimated one rep max or a known-max percentage table depending on the mode selected. It also includes projected training weights and rep-based estimates.

This gives you both a headline 1RM number and practical training weights you can use right away.

One rep max calculator tips

Frequently asked questions

What is one rep max?

One rep max is the heaviest weight you can lift for one complete repetition with proper form.

Do I need to test a true max?

No. Many people estimate their one rep max from a normal work set instead.

Which 1RM formula is best?

Different formulas can work well, and many people use the average of several formulas for a balanced estimate.

Are 1RM estimates exact?

No. They are useful training estimates and can vary based on reps, fatigue, technique, and exercise type.