Estimated 1RM

e1RM is short for estimated one-rep max. It answers a simple question: based on the weight you just lifted, the reps you got, and how hard it was, what would your single have been? Get that estimate from every working set and you have a strength curve that updates almost every session, no max-out required.

What e1RM is

A true one-rep max is one data point, taken rarely, on a day that may or may not represent your real strength. e1RM flips that. Every set you log becomes a small experiment that predicts the same underlying number, so instead of one noisy reading a few times a year you get a running estimate you can trend.

The catch is that the estimate is only as good as the RPE you feed it. That is why the honest rating covered in the RPE guide is the whole foundation. Garbage RPE in, garbage e1RM out.

The formula POWALIFTA uses

The app uses an RPE-percentage model in the Tuchscherer tradition. Every rep below a true single, and every RPE point below 10, shaves a fixed slice off the estimate. That fixed slice is one thirtieth, or about 3.33%.

Read it in plain English: count how far the set was from a maximal single. Two things push it away from a max. First, extra reps: a triple is two reps past a single. Second, reps left in the tank: an RPE 8 left two more. Add those, multiply by 3.33%, and that is the discount off your estimated single.

A worked example

Say you squat 140 kg for 3 reps and rate it RPE 8.

Next week the same triple feels like an RPE 7, meaning you had three in the tank instead of two. The distance from max drops to 5, and the estimate climbs to roughly 167 kg on the identical bar weight. Nothing on the bar changed, but the set told you your ceiling moved. That is the signal a percentage program would have missed entirely.

A quick reference table

You do not need to memorise this, but it helps to see how much of your e1RM a given set represents. These are the exact percentages the formula produces.

Variant multipliers

A paused squat and a competition squat are not the same lift, so comparing their raw e1RMs would be unfair to the harder one. POWALIFTA normalises this with a multiplier per variant, where the competition lift is the 1.0 baseline and harder variants scale the estimate up to a competition-equivalent number.

So a tempo squat e1RM of 150 kg is charted as 150 × 1.12 = 168 kg of competition-equivalent strength. This is why your progress chart can blend heavy competition work with harder variant days and still read as one honest line instead of a sawtooth.

Why it beats testing a max

Testing a true single has real costs. It is fatiguing, it eats into a training day, and it carries the most injury risk of anything you do. Worst of all it is a single sample: miss on a bad day and you conclude you got weaker when you did not.

• Frequency. e1RM updates from ordinary work, so you see the trend in weeks, not months.
• Lower risk. No maximal grinders means no maximal grinder injuries.
• Noise cancellation. One flat day barely dents a line built from dozens of sets.
• It respects readiness. Because it rides on RPE, a strong day and a weak day both produce a fair estimate.

Save the true max for the platform, where it counts. In training, let the math read your strength off the work you were already doing.