Enter your athlete's average daily training load over the last 7 days (acute) and last 28 days (chronic) — typically session-RPE or sRPE × duration. The calculator returns the ratio plus a zone interpretation.
What this calculator is doing
ACWR is the ratio of your athlete's last 7 days of training load (acute) to their last 28 days (chronic). Acute represents what they're absorbing right now; chronic represents what they've adapted to. A ratio significantly above 1.0 means recent training is higher than the athlete's baseline — useful as a flag for when fitness and fatigue might be drifting apart.
This tool uses the simple rolling-average formula (mean of last 7 days ÷ mean of last 28 days). The thresholds come from Gabbett's 2016 work, which is widely cited but also widely not universally replicated. Impellizzeri et al. (2020) showed the original "sweet spot" finding contains mathematical artefacts from overlapping windows, so don't treat 0.8–1.3 as a hard decision rule — use it as a prompt to check wellness, sleep, and the rest of the week's plan.
What does "training load" mean here?
Anything consistent across days. The two most common options:
- Session-RPE × duration (sRPE load) — the athlete rates the session 1–10 after training, multiplied by the session duration in minutes. Most common in team sports.
- GPS-derived total distance or PlayerLoad — for teams with wearables, this is more objective.
ACWR is dimensionless, so the unit doesn't matter as long as both windows use the same one.
Want this computed automatically?
Performance House logs daily sRPE through the wellness check-in and plots the rolling 7:28 ratio for every athlete. The same computeAcwrSeries() function powers both this calculator and the in-app chart. Coaches see the sweet-spot band shaded green, danger zone in red, and get alerted when an athlete drifts outside.
For the full formula, worked example, and research caveats, see the full ACWR guide.