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 runs from 60% to 100% in 5% steps, so you can read these loads 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.

Does the calculator keep what I enter?

The values exist only in the open page and are not written to browser storage, so reloading the page clears them. All calculations run 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)

Results are for informational purposes and do not constitute medical advice.

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 multiplies 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 comes from Boyd Epley's 1985 training manual and remains a common 1RM estimator in strength and conditioning. The Brzycki formula was published by Matt Brzycki in the Journal of Physical Education, Recreation & Dance (1993). Both are population-average models and are most accurate on sets of 3 to 5 reps. Accuracy decreases above 10 reps as muscular endurance 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 10)
Browser API: Pure JavaScript arithmetic. No library

Related operations

For estimating daily energy needs for a training plan, try the calorie calculator. To turn bodyweight and height into an estimated lean mass, 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 runs from 60% to 100% in 5% steps, so you can read these loads 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.
Does the calculator keep what I enter?: The values exist only in the open page and are not written to browser storage, so reloading the page clears them. All calculations run in your browser. Our servers are not involved at any point.

Last reviewed September 30, 2026

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