Free Strength Standards API
The FitnessVolt Strength Standards API is a free, read-only, CORS-enabled JSON API. Any site can pull strength percentile tables and the FitnessVolt Strength Score directly from these endpoints, no key required, as long as you keep the attribution link.
Two populations are served and kept strictly separate: verified competition percentiles from the public OpenPowerlifting dataset (squat, bench press, deadlift), and self-reported gym percentiles from the Symmetric Strength dataset (all supported lifts). They are never blended into a single number, and every figure is labelled with its source and sample size.
License & Attribution
The data is free to use under CC BY 4.0. The only requirement is a visible attribution link back to FitnessVolt on any page or product that displays it.
- Attribution text
- Powered by FitnessVolt
- Attribution link
- https://fitnessvolt.com/strength-standards/
- License
- CC BY 4.0 - free with attribution link
Every API response includes an attribution object carrying exactly this text, link, and license, plus a meta object describing the data source(s), sample sizes, and generation time.
Endpoints
Base URL: https://fitnessvolt.com/wp-json/rpe-training/v1
GET
/public/lifts
List every supported lift and whether it has verified competition data, gym data, or both.
https://fitnessvolt.com/wp-json/rpe-training/v1/public/lifts
GET
/public/standards/{lift}
Percentile tables (by weight class) for a lift, one block per population. Verified (OpenPowerlifting) and gym (Symmetric Strength) are returned separately, each labelled with source and sample size. Never blended.
lift- Path segment. One of the slugs from /public/lifts (e.g. bench-press).
sex- male | female. Default male.
unit- lb | kg. Output unit for weights. Default lb.
https://fitnessvolt.com/wp-json/rpe-training/v1/public/standards/bench-press?sex=male&unit=lb
GET
/public/rank
Dual percentile (verified + gym, separately) plus the FitnessVolt Strength Score and tier for a single lift attempt. Recomputed server-side.
lift- Required. Lift slug.
sex- Required. male | female.
bw- Required. Bodyweight in the chosen unit.
e1rm- Required. Estimated one-rep max in the chosen unit.
age- Optional. Refines the gym cohort.
unit- lb | kg. Default lb.
GET
/public/score
Just the FitnessVolt Strength Score (0-100) and tier for a lift attempt, with the labelled population it came from.
lift- Required. Lift slug.
sex- Required. male | female.
bw- Required. Bodyweight in the chosen unit.
e1rm- Required. Estimated one-rep max in the chosen unit.
age- Optional.
unit- lb | kg. Default lb.
Supported Lifts
| Lift | Slug | Verified (competition) | Gym (self-reported) |
|---|---|---|---|
| Back Squat | squat |
Yes | Yes |
| Bench Press | bench-press |
Yes | Yes |
| Deadlift | deadlift |
Yes | Yes |
| Front Squat | front-squat |
No | Yes |
| Sumo Deadlift | sumo-deadlift |
No | Yes |
| Power Clean | power-clean |
No | Yes |
| Incline Bench Press | incline-bench-press |
No | Yes |
| Overhead Press | overhead-press |
No | Yes |
| Push Press | push-press |
No | Yes |
| Snatch Press | snatch-press |
No | Yes |
| Dip | dip |
No | Yes |
| Chin-Up | chin-up |
No | Yes |
| Pull-Up | pull-up |
No | Yes |
| Pendlay Row | pendlay-row |
No | Yes |
Embeddable Widgets
Copy and paste these snippets into your site. Both keep the required Powered by FitnessVolt attribution link, so they satisfy the CC BY 4.0 license out of the box. Change the lift, sex, bw, e1rm, and unit values to suit.
1. Strength Score badge
A self-updating SVG badge (served as an image, no JavaScript required):
Live preview:
2. Percentile table
Pulls a lift's percentile table from the CORS-enabled JSON endpoint and renders it client-side, with the attribution link appended automatically:
Cite This Data
If you use this data in an article, study, app, or visualization, please credit FitnessVolt with a link. The license is CC BY 4.0: free to use, adapt, and redistribute with attribution.
Attribution (HTML)
Citation (APA)
Underlying sources to cite alongside FitnessVolt where relevant: the OpenPowerlifting dataset (verified competition results) and the Symmetric Strength dataset (self-reported gym lifts).
Notes
- All endpoints are public reads. They send
Access-Control-Allow-Origin: *so they can be called from any origin, and a one-hourCache-Control. - Requests are rate limited per IP. Keep usage reasonable and cache responses on your side.
- Cohorts below a minimum sample size are omitted rather than shown with an unreliable percentile.
- Scores and percentiles are always recomputed server-side. See the methodology for how the FitnessVolt Strength Score is built.