RPE to Load Calculator
Convert a target RPE and rep count into a working weight from your one-rep max — autoregulate your training load.
How it works
RIR = 10 − RPE · total reps to failure = planned reps + RIR · %1RM = 100 ÷ (1 + total reps ÷ 30) · load = 1RM × %1RM
RPE (rate of perceived exertion) rates how hard a set felt on a 1–10 scale, where RPE 10 is a true maximum and each point below leaves one more rep "in reserve". Converting RPE to reps-in-reserve, then estimating how many total reps that weight allows, lets you back out the intensity and the actual load. This is the backbone of autoregulated training, where the weight adjusts to how you feel that day.
Worked example
For a 300 lb max, 5 reps at RPE 8: RPE 8 means 2 reps in reserve, so the weight allows 7 reps to failure. %1RM = 100 ÷ (1 + 7/30) = 81.1%, or about 243 lb rounded to 5 lb.
Frequently asked questions
What does RPE 8 mean?
RPE 8 means you finished the set with about 2 reps left in the tank — hard but not maximal. RPE 10 means you could not have done another rep with good form.
Why use RPE instead of fixed percentages?
Your true strength fluctuates day to day with sleep, stress and fatigue. RPE lets the load float so a hard day is not forced onto a percentage you cannot hit, and an easy day is not left too light.
Is the load estimate exact?
No. RPE is a trained skill and the rep-to-percentage model is an approximation, so treat the number as a starting weight and adjust by feel on the next set.
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Educational estimate for training planning, not medical or coaching advice. Warm up, use good form, and progress gradually — stop if you feel pain.