RPE Calculator

Understand Your RPE Result

The calculator can answer three different questions. RPE and reps left translates effort. Plan a Set estimates a target weight from a completed set. Back-off weight applies the percentage reduction you choose.

In Plan a Set, the target weight appears first because it is the number you can use in your next workout. The estimated 1RM appears underneath so you can see how the target was produced. Both are estimates, not promises.

Plan Your Set with Weight, Reps and RPE

Start with one hard set from the same exercise and setup you want to plan. Enter the weight, clean reps and either the RPE or the number of clean reps you believe you had left.

Then choose the reps and effort you want for the target set. RPE 10 means no clean reps left, RPE 9 means about one, RPE 8 means about two and RPE 7 means about three.

Completed weight

Use the full weight exactly as you record it for this exercise.

Completed reps

Count clean reps with the same technique and range of motion.

Completed effort

Choose RPE or reps left, whichever you can judge more honestly.

Target reps and effort

Choose what you want to perform next for the same exercise and setup.

Compare Your Target Weights at Different RPEs

The chart keeps your target reps fixed and changes only the target effort. A lower target RPE leaves more reps in reserve, so the estimated weight is lower. A higher target RPE moves closer to your estimated limit.

Use the chart to compare options, then round the answer to a weight your equipment allows. Start conservatively when your setup, exercise variation or readiness has changed.

How the RPE Calculator Estimates Your Target Weight

The calculator first turns RPE into estimated reps left. It adds those reps to your completed reps, then uses the Brzycki equation to estimate a one-rep max. Finally, it works backward from your target reps and target RPE to estimate the target weight.

This is a transparent planning model. Research supports the RPE/RIR scale and the rep-max equation separately, but the combined target-RPE calculation has not been directly validated as a universal prescription.

RPE Target Weight Example

Select Plan a Set, then Use example to try these completed-set and target-set inputs.

How Accurate Is an RPE Weight Estimate?

Your RPE or reps-left rating has the biggest effect on the answer. Experience, exercise choice, fatigue and how close the set was to failure can all change how accurately you judge reps left. Compare results only when the exercise, setup, technique and weight convention stay the same.

The model supports completed and target effective-rep counts up to 10. If completed reps plus reps left, or target reps plus target reps left, exceeds 10, the calculator asks for a closer-to-failure set or target instead of stretching the equation beyond its supported range.

Sources and method notes

• Zourdos et al. — resistance-training RPE scale based on repetitions in reserve.
• Helms et al. — applying the repetitions-in-reserve RPE scale.
• Brzycki — predicting a one-rep max from repetitions to fatigue.
• Hughes et al. — accuracy of repetitions-in-reserve predictions.

Related Strength Tools

• Bench Press 1 Rep Max Calculator

  Use it when the completed set was a barbell bench press and you want bench-specific rep-max guidance.

• Barbell Squat 1 Rep Max Calculator

  Use it when the completed set was a barbell squat and you want squat-specific estimates.

• Deadlift 1 Rep Max Calculator

  Use it when the completed set was a deadlift and you want deadlift-specific estimates.