One Rep Max Calculator for Bodybuilding

Calculate your 1RM to program effective hypertrophy training. Use percentages to hit optimal rep ranges for muscle growth.

Most popular, 1-10 reps
Better for 8-15 reps
Conservative estimate
Power-based formula
Average of all formulas

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Complete Guide: One Rep Max Calculator for Bodybuilding

Calculate your 1RM to program effective hypertrophy training. Use percentages to hit optimal rep ranges for muscle growth.

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Expert Tips for Bodybuilding

  • Bodybuilders don't need to test true 1RMs - estimate from 6-12 rep sets
  • Use 1RM to calculate working weights for different rep ranges
  • 70-85% of 1RM is typically the hypertrophy sweet spot
  • Track 1RM progress even if you never lift maximally
  • Different exercises may have different optimal percentages
  • Combine percentage-based training with RPE for best results

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Frequently Asked Questions

Do bodybuilders need to know their 1RM?

It's useful for programming but not essential. Many successful bodybuilders never test true maxes. Use it as a tool for progressive overload tracking.

What percentage of 1RM for hypertrophy?

Generally 65-85% of 1RM, which typically allows 6-15 reps. The 8-12 rep range (70-80% 1RM) is the traditional hypertrophy zone.

Should I test 1RM on isolation exercises?

No - it's dangerous and unnecessary. Calculate 1RM only for compound lifts. Use RPE or rep targets for isolation work.

How do I progress using 1RM?

Add 5-10 lbs to your estimated 1RM when you exceed your rep targets. This automatically increases working weights proportionally.

What's more important - 1RM or rep quality?

Rep quality. A controlled, full ROM rep builds more muscle than a sloppy heavy rep. Use 1RM for planning, not ego lifting.

Looking for the standard one rep max calculator?

Go to Main 1RM Calculator