How accurate is the squat 1RM calculation?

1RM formulas are most accurate for sets of 3–5 reps. The squat tends to have good formula accuracy because it is a strength-dominant movement. Sets above 10 reps may underestimate true 1RM due to cardiovascular fatigue.

What percentage of my 1RM should I use for training?

Common programming uses 70–85% for hypertrophy, 85–95% for strength, and 95–100%+ for peaking. The percentage table in this calculator shows these ranges so you can set your training weights directly.

Should I count the bar weight?

Yes. Enter the total weight on the bar including the bar itself (typically 20 kg / 45 lbs for a standard Olympic bar). The formula works on the total load lifted.

Is my data sent to a server?

All calculations are pure JavaScript running in your browser. Our servers are not involved at any point.

Squat one rep max calculator

Enter the weight and reps from your squat to estimate your one rep max (1RM) and generate a full percentage training table. The Epley and Brzycki formulas are both shown so you can see the range of estimates.

Exercise

Weight lifted (kg)

Reps performed (1–12)

How it works

Two formulas are used and averaged. The Epley formula (1985): 1RM = weight × (1 + 0.0333 × reps). The Brzycki formula (1993): 1RM = weight × 36 / (37 − reps). Both assume a near-maximal set of 1–12 reps. The percentage table divides the estimated 1RM by each percentage to give your working weight for that intensity zone. All arithmetic runs locally in your browser.

Processing runs in your browser

All calculations happen locally using pure JavaScript. Our servers are not involved at any point.

Technical specification

The Epley formula was published by Boyd Epley (1985) and remains the most widely used 1RM estimator in strength and conditioning. The Brzycki formula was published by Matt Brzycki in Strength & Conditioning Journal (1993). Both are population-average models with a standard error of approximately ±3–5 kg on sets of 3–5 reps. Accuracy decreases above 10 reps as aerobic capacity increasingly influences performance.

Epley formula: weight × (1 + 0.0333 × reps)
Brzycki formula: weight × 36 / (37 − reps)
Valid rep range: 1–12 reps (accuracy decreases above 8)
Browser API: Pure JavaScript arithmetic. No library

Related operations

For estimating daily energy needs for a training plan, try the calorie calculator. To track fat-free mass between training blocks, use the lean body mass calculator. For setting cardio targets alongside strength work, see the heart rate calculator.

Frequently asked questions

How accurate is the squat 1RM calculation?: 1RM formulas are most accurate for sets of 3–5 reps. The squat tends to have good formula accuracy because it is a strength-dominant movement. Sets above 10 reps may underestimate true 1RM due to cardiovascular fatigue.
What percentage of my 1RM should I use for training?: Common programming uses 70–85% for hypertrophy, 85–95% for strength, and 95–100%+ for peaking. The percentage table in this calculator shows these ranges so you can set your training weights directly.
Should I count the bar weight?: Yes. Enter the total weight on the bar including the bar itself (typically 20 kg / 45 lbs for a standard Olympic bar). The formula works on the total load lifted.
Is my data sent to a server?: All calculations are pure JavaScript running in your browser. Our servers are not involved at any point.

Last reviewed May 26, 2026