SuCalc
Health & Fitness

RPE and RIR Load Calculator

Updated Aug 26, 2026 Reviewed Aug 26, 2026
Convert RPE and repetitions in reserve, estimate percentage of one-rep max, calculate a rounded target load, or estimate 1RM from a completed set.

Effort-based strength estimate

Enter load, repetitions and perceived effort

Use a recent exercise-specific estimate.

Use consistent repetitions from one continuous set.

6–10 in 0.5 steps; RPE 10 maps to 0 RIR.

Subjective estimate, not a load prescription
RPE accuracy varies by experience, exercise and fatigue. The result does not assess today's readiness or safety.

Result

Calculation summary

Enter values to see the result

Your result, breakdown, assumptions, and warnings will appear here.

Live effort preview

RPE, RIR and estimated intensity

RPE ↔ RIR
The gauge visualizes the selected effort; values update as load, repetitions and effort change.

%1RM = 100 ÷ (1 + (reps + RIR) ÷ 30)

Effective RPE8
Effective RIR2
Estimated %1RM81.1%

How to use this calculator

  1. 1Choose target-load or estimated-1RM mode.
  2. 2Enter repetitions and RPE or RIR.
  3. 3Review the rounded result and comparison table.

Formula

RIR = 10 − RPE; %1RM = 100 ÷ (1 + (reps + RIR) ÷ 30)

The model extends Epley by treating performed repetitions plus RIR as equivalent repetitions to failure.

Calculation steps

  • Synchronize RPE and RIR.
  • Calculate equivalent repetitions and estimated intensity.
  • Calculate and round load or estimate 1RM.

Worked example

Five repetitions at RPE 8 equal 2 RIR and about 81.1% of estimated 1RM in this model.

Assumptions

  • Effort is subjective.
  • Technique and range of motion are consistent.
  • The model is an estimate.
  • Higher repetitions add uncertainty.

Sources

Frequently asked questions

Is RPE 8 always exactly 2 RIR?

The scale maps it that way, but real perception varies.

Why do charts differ?

Charts use different data or equations; this tool exposes its model.

Can it estimate 1RM?

Yes, from a completed submaximal set.

Is the target a prescription?

No; readiness and safety are outside scope.

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