Resources · free tool

Estimate your 1-rep max

Enter one honest set: the weight, the reps, and how close to failure you got. You'll get your estimated max (your e1RM) plus the right load for every rep range. It's an estimate, not a tested max, and it runs in your browser, so nothing leaves your device.

5
Estimated 1-rep max (e1RM)
112.5 kg
Likely range
112.5-117.5 kg
From 100 kg × 5 reps (to failure).
Reliable estimate

What you can lift drops as the reps climb. Each bar is the load as a share of your max.

Strength (1-5) Hypertrophy (6-12) Endurance (12+)
Loads
Reps% of maxLoad (kg)Use
1100%112.5 kgStrength
297%110 kgStrength
394%107.5 kgStrength
492%102.5 kgStrength
589%100 kgStrength
686%97.5 kgHypertrophy
881%90 kgHypertrophy
1075%85 kgHypertrophy
1271%80 kgHypertrophy
1567%75 kgEndurance
2060%67.5 kgEndurance

These are estimates, not a tested max. They're most accurate from sets of 3-8 reps. Very heavy singles, or sets past ~12, get rougher.

Max strength

1-5 reps · ~85-100%

Heavy loads, low reps, long rests (3-5 min). Builds raw force. Leave a rep in the tank on most sets, since true singles are taxing.

Muscle & size

6-12 reps · ~67-85%

Moderate loads, 1-3 min rests, sets pushed close to failure (1-3 left). The sweet spot for building muscle.

Endurance & work

12+ reps · under ~67%

Lighter loads, high reps, short rests. Builds stamina and work capacity, and goes easy on the joints. Good for conditioning and accessories.

Your numbers stay on your device.

Your max is estimated from the set you enter, not measured. The maths blends two established formulas (Brzycki under 10 reps, Epley above) and lines up with the usual rep-percentage charts; lift type nudges the curve, since squats and deadlifts hold more reps at a given percentage than pressing does. How close to failure you went matters most: a set with reps to spare points to a higher max than the same set to failure. Treat the loads as a starting point. Don't test a true max without a warm-up and a spotter, and if you're injured or new to lifting, get a coach first.

When you want it programmed

Want these numbers in a real plan?

Knowing your max is step one. A coach turns it into week-to-week loading that actually moves: choosing the rep ranges, managing fatigue, and adjusting to how you're lifting instead of a fixed chart.