How the strength tier is worked out

What the tier is

Five barbell lifts are placed on a five-step scale — untrained, novice, intermediate, advanced, elite — against published tables for your sex, bodyweight and age band ¹. The scale is a classification of lifters rather than a survey of a population, so it says where a lift sits among people who lift, not what fraction of the public you would out-lift. The companion page on strength for endurance covers that distinction and why it rules out a percentile.

This page is about the arithmetic underneath: which lifts, which rep counts, and what happens at the edges of the published data.

The five lifts, and what counts

The tables are written for a specific movement performed a specific way. A half squat is not the squat in the table, and a pressed-out clean is not the clean. If your logged lift does not meet the definition, the tier it produces is measuring something else.

• Bench press — bar touches the chest with a pause, pressed to full elbow extension.
• Back squat — thighs travel below parallel to the floor.
• Deadlift — knees, hips and upper back fully extended at lockout.
• Overhead press — strict: knees straight, torso upright, elbows fully extended.
• Power clean — bar caught at or above a 90° knee angle.

Anything outside those five gets no tier. A lateral raise has no published standard, and inventing one to fill the space would be the app expressing an opinion where it promised to show a source.

Where your number comes from

A tier needs a one-rep maximum. If you logged a single, that is the number. If you logged a heavier-rep set, the app converts it, and the conversion is imperfect in a known direction — of seven equations tested against measured maxima, every one underestimated the deadlift, by nine to fourteen per cent on average ². The deadlift row says so where it appears.

Sets beyond ten repetitions are ignored rather than converted. The equations lose accuracy as the rep count climbs, and a tier built on a set of twenty would be a guess wearing a badge.

Between the published classes

The source publishes one row per bodyweight class. Almost nobody weighs exactly a class boundary, so the app interpolates between the two rows either side rather than snapping to the nearest — a 70 kg lifter is not judged against the 67 kg row.

Outside the published range it clamps instead. The top class is open-ended, so a lifter above it reads against that last published row rather than having the trend extended past where anyone measured. The same holds at the light end. Extrapolation would invent numbers; clamping just stops.

When you get no tier at all

The tables cover ages 18 to 69 in four bands, and they are sex-specific. Miss any input the source needs — no sex on the profile, no bodyweight, an age outside that range — and the app shows nothing and names the missing field rather than filling it with a default.

That is deliberate. A tier computed from an assumed bodyweight is a number the athlete did not give us, presented with the same confidence as one they did.

What we changed, and what we left alone

The values are transcribed from the published kilogram tables, with four changes of two different kinds. Two are ordering breaks: a tier that would rank below the one beneath it, which no reading of the source can have intended. Two are values a fraction off the 2.5 kg grid the tables otherwise keep, snapped back — tidying rather than repair.

Several further oddities were left exactly as published. They look wrong against their neighbours, but they do not break the tier ordering, and quietly correcting a source because we disagree with it would make the table ours rather than theirs. All four changes and every value left alone are listed in the code beside the tables.

References

Numbered in order of first appearance. Every link goes to the original work.

1. Kilgore. Weightlifting performance standards (bench press, squat, deadlift, press, power clean). ExRx.net. 2023.
2. LeSuer, McCormick, Mayhew, Wasserstein & Arnold. The accuracy of prediction equations for estimating 1-RM performance in the bench press, squat, and deadlift. Journal of Strength and Conditioning Research. 1997.