RPE Calculator
What weight is 8 reps at RPE 8? Enter your 1RM, reps and RPE (or RIR) and this free calculator gives you the weight from the RTS RPE chart. It also works backwards to estimate your 1RM from a set. No sign-up.
Don’t know your 1RM? Switch to Estimate 1RM, or use the 1RM calculator.
How to use the RPE calculator
Choose Find a weight to turn a prescription like 5 @ RPE 8 into a load from your 1RM, or Estimate 1RM to work out your max from a set you’ve done. Switch between RPE and RIR (reps in reserve) to match how your programme is written.
Percentages come from Mike Tuchscherer’s Reactive Training Systems chart. You also get a full chart of weights for 1–12 reps at RPE 6–10 from your 1RM.
Frequently asked questions
Rate of perceived exertion: how hard a set was on a 1–10 scale. RPE 10 means you couldn’t have done another rep, RPE 9 means one rep left, RPE 8 means two left.
They describe the same thing from opposite ends. RIR (reps in reserve) counts the reps you had left, so RIR = 10 − RPE. RPE 8 is 2 RIR.
It depends on the reps. A single at RPE 8 is about 92% of your 1RM, 5 reps at RPE 8 is about 81%, and 8 reps at RPE 8 is about 74%, on the RTS chart.
Effort ratings get much less accurate on high-rep sets, and so do 1RM estimates. Past 12 reps the numbers stop being useful.
Your maxes, kept up to date.
SYNCT estimates your 1RM from every set you log, so the number you plug into your RPE chart is never months out of date.
