What rep range is best for predicting 1RM?

Sets of 3 to 6 reps yield the highest predictive accuracy for 1RM calculators.

Is 1RM the same for bench, squat, and deadlift?

The formula applies to all major compound lifts, but each exercise has its own independent 1RM value.

One Rep Max Calculator

Use this free one rep max calculator (1RM calculator) to estimate your maximum lifting strength without risking injury, with full percentage training load breakdowns.

How to use this calculator

Enter the weight lifted on a submaximal set (e.g. bench press, squat, deadlift).
Enter the number of successful, full-range repetitions performed (best results between 2 and 10 reps).
View estimated 1RM across Epley and Brzycki equations along with a complete training percentage table.

Formula & method

Epley & Brzycki 1RM Formulas

Epley 1RM = Weight × (1 + Reps ÷ 30) · Brzycki 1RM = Weight × (36 ÷ (37 − Reps))

Calculations assume strict form and minimal resting between reps in the tested set.

Example

Lifting 100 kg for 5 reps → Epley 1RM = 100 × (1 + 5/30) = 116.7 kg.

Key insights

Estimating 1RM from submaximal sets (3–6 reps) prevents Central Nervous System fatigue and acute lifting injury.
The Epley formula tends to be slightly more accurate for sets under 10 reps, while Brzycki is preferred for higher reps.
95% of 1RM corresponds roughly to 2 reps, 90% to 4 reps, 80% to 8 reps, and 75% to 10 reps.

How to interpret your result

Estimated 1RM

The maximum theoretical weight you can lift for a single successful repetition.

Training Percentages

Target load recommendations for hypertrophy (75–85%), strength (85–95%), or power.

Frequently asked questions

What rep range is best for predicting 1RM?: Sets of 3 to 6 reps yield the highest predictive accuracy for 1RM calculators.
Is 1RM the same for bench, squat, and deadlift?: The formula applies to all major compound lifts, but each exercise has its own independent 1RM value.

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