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One Rep Max Calculator - Estimate Your 1RM

Estimate your one rep max from weight and reps. Calculate 1RM using popular strength formulas and view estimated weights for different rep ranges.

Sports Tools

One Rep Max Calculator

Estimate your one rep max from the weight you lifted and the number of reps completed. Useful for strength training, powerlifting, and workout planning.

Estimated 1RM

Average estimate

114.6 kg

Based on 100 kg × 5 reps

Epley formula

116.7 kg

Brzycki formula

112.5 kg

Estimated weight by reps

1 rep

110.9 kg

2 reps

107.4 kg

3 reps

104.2 kg

4 reps

101.1 kg

5 reps

98.2 kg

6 reps

95.5 kg

8 reps

90.5 kg

10 reps

85.9 kg

12 reps

81.8 kg

One rep max formulas are estimates. Actual max strength can vary based on technique, fatigue, equipment, and safety.

Best for 1 to 12 reps. Higher reps are less accurate.

Quick examples

Use this for bench press, squat, deadlift, overhead press, and other strength exercises.

Discover more tools

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How this one rep max calculator works

Enter the weight you lifted.

Choose kg or lb.

Enter the number of reps completed.

View your estimated one rep max and rep range estimates.

Frequently Asked Questions

What is a one rep max?

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

Is the result exact?

No. One rep max formulas are estimates. Actual strength can vary based on form, fatigue, and exercise type.

Which exercises can I use this for?

You can use it for common strength movements such as bench press, squat, deadlift, and overhead press.