THE TAKEAWAY

Your estimated max is a planning tool. Compare like-for-like sets and use the result for the same exercise.

Start with a set you already know

A one-rep max is the most weight you can complete once on a particular exercise. A multi-rep set can also be used to estimate that number. An estimate and an actual maximum test are different measurements.

Sources: HPRC: What is a one-rep max?

Enter the right numbers

In IronMath Fitness, weight means the total external load: the bar plus both sides. Reps means completed repetitions from that set. Choose lb or kg before comparing the output with your training log.

  • Use the same exercise and range of motion each time.
  • Enter complete repetitions, not a partial final attempt.
  • Record the date and your actual set alongside the estimate.

A worked example

For 200 lb × 5 reps, IronMath Fitness calculates 233.3 lb with Epley and 225 lb with Brzycki. The displayed average is 229.2 lb. The two formulas give different answers because they model the relationship between weight and reps differently.

For a one-rep input, IronMath Fitness returns the weight you entered. There is no additional estimate to make.

Use it without chasing it

If your program asks for 75% of your estimated maximum, multiply 229.2 by 0.75: approximately 171.9 lb. Then check the percentage and plate tools for a load you can assemble. That arithmetic does not establish which percentage is appropriate for you.

Keep each exercise separate. A squat estimate is not a bench press target. If technique, fatigue, or the rep count changes, treat comparisons cautiously.

Sources: HPRC: What is a one-rep max? · NSCA: Intensity or resistance

PUT IT INTO PRACTICE

Check your own numbers.

Open calculator

Sources & approach

This guide combines linked references with IronMath Fitness examples. It provides general information, not a personal training plan.