How accurate are 1RM calculators?

1RM calculators are generally accurate within 5-10% when used with rep ranges under 10. The accuracy depends on factors like training experience, muscle fiber composition, and the specific formula used. Our calculator uses 7 different formulas to give you the most comprehensive estimate.

Which 1RM formula is most accurate?

The Epley formula is most widely used and accurate for most people, especially with rep ranges of 2-10. However, different formulas work better for different individuals. Brzycki tends to be conservative, while Lombardi works well for powerlifters. Our calculator shows all 7 formulas so you can compare.

Can I use this for any exercise?

Yes, you can use 1RM calculators for any compound exercise like bench press, squat, deadlift, overhead press, and rows. The formulas are based on general strength principles that apply across exercises, though they're most accurate for compound movements.

What rep range should I use for the most accurate calculation?

For best accuracy, use rep ranges between 2-10 reps. The sweet spot is 3-8 reps where most formulas perform optimally. Avoid using very high rep ranges (15+) as the formulas become less reliable due to muscular endurance factors.

How often should I recalculate my 1RM?

Recalculate your 1RM every 4-6 weeks or whenever you notice significant strength gains. For beginners, monthly calculations work well. Advanced lifters might recalculate every 6-8 weeks. Always use recent max effort sets for the most accurate results.

Deload — Strength Training Glossary

A deload is a planned reduction in training intensity or volume (typically 40-60% of normal) to dissipate accumulated fatigue and restore performance.

Deloads are scheduled — typically every 4-8 weeks for trained lifters — rather than reactive. The goal is to drop fatigue without losing fitness, allowing the next training block to start fresh.

A standard deload week reduces working weights to 50-60% of normal load while keeping set/rep schemes similar. More aggressive deloads cut volume by 40-50% as well. After a deload week, working weights return to normal or slightly higher; the lifter feels stronger because cumulative fatigue has been cleared.

Deload

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