ACWR calculator (acute:chronic workload)
Last updated: April 28, 2026
ACWR (Acute:Chronic Workload Ratio) compares your last 7-day load (acute) to the 28-day weekly average (chronic). Above 1.5, injury risk rises significantly (Gabbett, 2016).
The tool places you in a risk zone (undertraining, sweet spot, caution, danger) and gives the action to take.
ACWR ratio
Risk zone
Reference: Gabbett TJ. Br J Sports Med 2016. Calculation: acute (sum 7d) ÷ chronic (weekly average over 28d).
The calculation
ACWR = acute load (last 7-day sum) / chronic load (weekly avg over 28 days)
- Arbitrary units (sRPE): session RPE × duration in minutes. Universal.
- Kilometres: for running.
- Tonnage: sets × reps × load, for strength and powerlifting.
The 4 zones
- < 0.8 (undertraining): doing less than average. Risk of detraining.
- 0.8 to 1.3 (sweet spot): optimal zone, adaptation and progression.
- 1.3 to 1.5 (caution): load rising faster than absorption capacity. Watch fatigue, sleep, signals.
- > 1.5 (danger): significantly increased injury risk. Reduce next week.
Coach use
ACWR is widely used in team athletic prep and sports physiotherapy. Indicators: post-injury return (ratio < 1.3), peak season (tolerate 1.3-1.5 for 1-2 weeks then deload), back-to-back competitions.
FAQ
Which unit for my discipline?
Running: km. Strength: tonnage. Team sports or hybrid: sRPE. The ratio works regardless of unit, as long as it stays consistent.
Daily calculation needed?
Once a week is enough, end of week. For a whole team, automate the calc from your tracking tool.
Related disciplines
