RPE Calculator

RPE stands for Rate of Perceived Exertion. It is a number from 5 to 10. It tells you how hard a set was, based on how many reps you had left when you racked the bar.

RPE 10 means you had nothing left. RPE 9 means you had one more rep. RPE 8 means you had two.

Lifters use a version made by Mike Tuchscherer. He took the old 1-to-10 scale and made it exact to plan training with.

RPE exists because your 1RM moves. A fixed percentage assumes your max today is the same as the day you tested it. It usually is not. Sleep, stress, and food can all affect your performance.

RIR stands for Reps In Reserve. It is how many reps you could still have done.

You can flip one to get the other:

RIR = 10 − RPE

RPE 8 is 2 RIR. RPE 9 is 1 RIR. RPE 10 is 0 RIR. That is how RPE and RIR are related.

It's built on top of the RTS RPE chart by Mike Tuchscherer. It is a lookup, not a formula.

Five reps at RPE 8 is 2 reps left over. That is 7 reps to failure. The chart says 7 reps to failure is 81.1% of your 1RM.

Your estimated 1RM is the weight you lifted divided by that percentage. A target weight is your 1RM multiplied by that percentage.

e1RM means estimated 1-rep max. It is a guess of what you could lift for a single based on a set you've already done.

This page works it out by lookup in the RPE table.

Other calculators use a formula. Epley is the common one:

e1RM = weight × (1 + reps / 30)

Epley does not use RPE at all. That makes the formula simpler and less precise. A set of 5 to failure and a set of 5 with three reps left are not the same.

The chart is an average. Your numbers can drift from it because:

You are not the average. Two lifters with the same 1RM can hit different rep counts at 85%. Training history, build and technique all change it.

It changes between your own lifts. Most lifters get fewer reps at a given percent on deadlift than on squat. And fewer on squat than on bench.

RPE is a call, not a measurement. A set logged at RPE 8 that was really a 9 makes every number after it too big.

The further a set is from a single, the less you can trust the estimate.

A triple is close to a max, so it's a close guess. A set of 10 is a long guess. The gap between your rep strength and the chart’s average grows with every rep.

So check the reps yours came from. Use your heaviest low-rep sets, not your back-off sets. And read the number as a trend, not a weight to go and try.

Most programs use both.

Percentages are easy to plan. You can write 12 weeks up front, check the plan and add up the volume before anyone lifts.

RPE reacts to the day. After bad sleep or a hard week, a fixed 85% turns into a grinder.

So most coaches use both. In practice that means a top set to a target RPE. The back-off sets are usually a percentage of that top set.