1RM Calculator (Squat, Bench, Deadlift)

Estimate your one-rep max without testing it. Enter a weight you lifted for multiple reps, and this calculator predicts what you could lift for a single rep.

Use it to set training weights, track progress, or plan your next program. Most accurate with moderate rep ranges (3–6 reps) on compound lifts.

This assumes your RIR estimate is accurate.

Estimated 1RM

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Confidence: --

1RM formulas are estimates, not a test. They're most accurate when sets are hard and rep ranges are moderate.

How It Works

  • Weight: The load you lifted (in pounds or kilograms)
  • Reps: How many reps you completed with good form
  • Formula: We default to Epley (weight × (1 + reps/30)), with five other validated formulas for comparison
  • RIR (optional): If you had reps in reserve, enable this to factor in estimated effort

All formulas assume the set was taken close to failure. Accuracy decreases above 10 reps.

Example

If you bench press 225 lbs for 5 reps with no reps left in the tank, the Epley formula estimates your 1RM at approximately 262 lbs.

You could use this to set training percentages—for example, working sets at 80% would be around 210 lbs.

FAQ

No. It's a prediction based on the relationship between submaximal reps and max strength. Individual variation, technique, and fatigue all affect your true max. Use it as a planning tool, not gospel.

Generally no. Beginners benefit more from submaximal training. Use this calculator to estimate your max and base your training percentages on it. Save true max testing for when technique is solid.

Whenever you hit a new rep PR on a lift. If you squat 315×6 when you used to do 315×4, your estimated max has gone up. Recalculate and adjust training weights accordingly.

Yes, but deadlift estimates are most accurate at lower rep ranges (1–4 reps). Higher rep deadlifts accumulate more fatigue, which can skew predictions. Select "Deadlift" in the lift dropdown for adjusted confidence ratings.

Related Tools

Percentage Calculator

Turn your 1RM into training weights

Warm-Up Generator

Plan your warm-up sets