RPE
e RIR.
From perceived effort to the right load. Tell me your reps and RPE: I'll estimate the percentage of your one-rep max and the weight to load.
How it
works.
The estimate uses the RPE/RIR chart (Tuchscherer, validated by Zourdos and Helms): reps and RIR together determine the percentage. It's a guide, not a law: calibrate it to how you feel.
Other
calculators.
See allQuestions
about RPE and RIR.
RPE is perceived effort on a scale from 1 to 10: RPE 10 is a set taken to failure, RPE 8 means you could have done 2 more reps.
They're two sides of the same coin: RPE = 10 − RIR. Reps in reserve (RIR) are how many you had left: RPE 8 corresponds to 2 RIR.
You also need the number of reps: adding reps and RIR gives you the reps 'to failure', from which you estimate the percentage of your one-rep max. 5 reps at RPE 8, for example, work out to about 81%.
Percentages are objective but don't account for how your day is going; RPE adapts to how you feel. Many programs combine them: a baseline percentage, RPE to fine-tune.