1RM Calculator — Estimate Your One Rep Max | Apex

1RM Calculator

Estimate Your One Rep Max

Enter a weight you lifted and how many reps you got. Apex estimates your 1RM with the Epley and Brzycki formulas and turns it into training zones you can actually use.

Calculate your 1RM

Epley formula

Brzycki formula

Estimated 1RM (average)

Estimates update live as you type.

Training zones from your 1RM

Example based on a 100 kg 1RM — enter your lift above to personalize the table.

%1RMLoadTypical repsZone
95%95 kg2Max strength
90%90 kg4Max strength
85%85 kg6Strength
80%80 kg8Strength
75%75 kg10Hypertrophy
70%70 kg12Hypertrophy
65%65 kg15Endurance
60%60 kg20Endurance

What your 1RM estimate really tells you

Formula-based estimates are a starting point, not a verdict. Accuracy varies by exercise (they work best on big barbell lifts like the squat, bench press, and deadlift), by rep range, and by your training experience — beginners often land above or below the real number.

Never attempt a true max lift casually. If you decide to test a real 1RM, do it fresh, after a proper warm-up, with solid technique, safety pins or a spotter — and ideally with an experienced coach watching.

Apex logs every set, detects new PRs automatically, and updates your estimated 1RM per exercise over time — so your training percentages stay honest without max testing every month.

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Frequently Asked Questions

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