How the Weyt Age is computed.
Your Weyt Age is the age whose median person of your sex lifts what you lift. This page is the whole method, in the order the code runs it, with the sources and a worked example computed by that code.
Definition
The Weyt Age is the calendar age at which the median person of your sex, in the general population, lifts as much as you do. A 36-year-old whose bench press and squat match the median 25-year-old has a Weyt Age of 25. It is a rank expressed as an age, not an estimate of your biological age, and it moves only when your lifts move.
Two anchors: the flat barbell bench press (upper body) and the barbell back squat (lower body). One is enough for a first number; both make it exact.
Inputs
- Sex (male or female), because the published norms are sex-specific.
- Age, clamped to 14 to 95, to pick the age bracket and to compute the delta.
- Bodyweight, because the population norm is a weight-pushed-to-bodyweight ratio. On the landing page it defaults to the adult average for your sex until you change it; in the app it comes from your profile.
- One best set per anchor: weight and reps, 1 to 10 reps. In the app, every qualifying set you have ever logged is a candidate (see staleness below); on the landing page it is the set you type.
Step 1 · Estimate the one-rep max
Each set becomes an estimated one-rep max (e1RM) with the Epley formula: weight × (1 + reps ÷ 30). A set of 155 lb × 5 is an e1RM of about 181 lb. Sets above 10 reps are not used for a direct anchor because the formula drifts at high reps (proxy movements accept up to 15, with a confidence penalty). No max-out testing is ever asked for.
Step 2 · Score the bench against the general population
The bench e1RM is divided by bodyweight and looked up in the Cooper Institute one-repetition-maximum bench press norms by sex and age bracket (20 to 29, 30 to 39, 40 to 49, 50 to 59, 60 and over), as reprinted in ACSM's Guidelines for Exercise Testing and Prescription. That gives the percentile of same-sex, same-age adults you out-lift, and, inverted, the age bracket whose median matches your ratio. Interpolating across brackets turns the bracket into a continuous age.
Step 3 · Score the squat through the lifter standards
No credible general-population one-rep-max squat norms exist in the published literature. The squat is therefore scored in two moves. First, its e1RM is placed on the Strength Level squat standards for your sex, bodyweight and age, which gives a percentile among lifters who track their training. Second, the bench press that sits at that same percentile on the Strength Level bench standards is scored against the Cooper table exactly as in step 2. The two lifts end up on one calibrated scale, and a lifter with a strong squat and a weak bench is read correctly on both.
Step 4 · The median of the two
Each anchor yields an age. The Weyt Age is the median of the two, rounded to a whole year. The percentile shown beside it ("stronger than 80% of men your age") is the median of the two percentiles. A second ladder reports the same lifts against lifters who track (Strength Level), a much stronger, self-selected crowd; that number is usually older, and it is shown as the subline, never the headline.
Edge rules
Estimated anchors
When a direct barbell set is missing, the anchor is estimated from a related movement at the same Strength Level percentile (dumbbell, incline and machine presses, front and goblet squats, Bulgarian split squats, hack squats, and, with a real bodyweight on file, push-ups and bodyweight squats). With no squat at all, the squat is estimated at the bench's own percentile. An estimated anchor is labelled ESTIMATED wherever the number appears, and a direct set that beats the estimate replaces it; a proxy only overrides a direct set it beats by more than ten percent.
Below the youngest bracket
The published tables start at ages 20 to 29. A lifter above that bracket's median would otherwise stall at 25. Instead the age is extrapolated from the percentile within the youngest bracket: the 50th percentile reads 25, the 90th percentile and above reads 18, and the numbers in between are continuous. The result is marked as extrapolated in the data; the scale bottoms out at 18.
Current form, not all-time
In the app the anchor is the best staleness-discounted set, not the all-time best. A set keeps full credit for 28 days, then loses 0.75% of its value per week, floored at 80% of the original. A recent PR moves the number down; months off drift it up; a years-old test never disappears, it just counts for less. The landing-page check has no history, so it uses the set you type at full credit.
Worked example
A 36-year-old man at 200 lb who benches 155 lb × 5, computed by the same function the app and the calculator run:
| Input | Bench e1RM | Squat e1RM | Vs general population | Vs lifters who track | Weyt Age |
|---|---|---|---|---|---|
| Bench only | 181 lb | 244 lb (estimated at the bench percentile) | stronger than 47% | 17th percentile | 38 (estimated) |
| Bench + squat 205 × 5 | 181 lb | 239 lb (direct) | stronger than 45% | 17th percentile | 39 |
Calendar age 36; the delta is the Weyt Age minus the calendar age. Try your own numbers on the calculator; it runs in your browser and nothing you type is sent anywhere.
Sources
- The Cooper Institute, Physical Fitness Assessments and Norms for Adults and Law Enforcement, as reprinted in ACSM's Guidelines for Exercise Testing and Prescription, 8th ed., Table 4.9: bench press weight ratio (weight pushed ÷ body weight) by sex and age bracket.
- Epley, B. (1985). Poundage Chart. Boyd Epley Workout, Lincoln, NE. The one-rep-max estimate.
- Strength Level strength standards for the bench press and squat by sex, bodyweight and age (strengthlevel.com), the lifter ladder and the squat channel.
What the Weyt Age is not
- Not a biological or fitness age. It ranks two lifts against published norms and reports the rank as an age.
- Not a measure of health, endurance or body composition. A strong lifter with poor cardio still reads young.
- Not medical advice. weyt.ai provides AI-generated fitness guidance; talk to a physician before starting or changing a training program.
- Not a guess. The same inputs always give the same number, and a test pins the landing check, the calculator, the public API, the MCP tool and the app to one another.
Use it elsewhere
The computation is available without an account or key as a free endpoint, GET /api/public/weyt-age (spec at /openapi.json), and as a Model Context Protocol tool at /api/mcp. Every strength-standards page on this site is built from the same tables.