Acute:chronic workload ratio calculator (ACWR)
Enter the totals for the last four weeks and get the ratio between the current week and the period average. The methodology is explained below, and so are its limits.
Weekly total load (AU)
Each week's total, oldest to current. If you use the RPE calculator method, it is the sum of every session that week.
Acute load
3,100
Chronic load
2,650
Ratio
1.17
Acute load = current week. Chronic load = average of the four weeks, including the current one. Ratio = acute ÷ chronic.
What the ratio compares
The acute:chronic ratio relates what an athlete did this week to what they had been doing habitually. A value of 1 means this week matched the recent average; below, they did less; above, more. It measures change, not amount.
How this tool calculates it
Acute load is the current week's total. Chronic load is the average of the last four weeks, including the current one. This is the coupled rolling-average version, the most widespread and the easiest to reproduce by hand. There is another variant, the exponentially weighted moving average (EWMA), which weights recent days more and gives different values on the same data.
What it needs to mean anything
Four weeks of continuous logging. With less history the denominator is unstable and the ratio jumps for reasons that have nothing to do with training. That is the case for a recent signing or someone returning from injury: the number appears, but it does not describe anything yet.
What this number does not do
The acute:chronic ratio does not predict injuries. The ranges circulating as risk zones come from studies in specific populations — particular sports, levels and contexts — and do not transfer automatically to any athlete. Its methodology has been debated in the scientific literature, particularly over how the denominator is built. Use it as a signal of change in load, alongside what you see and what the athlete tells you, not as a traffic light that decides for you.
Frequently asked questions
- Which ratio is the right one?
- There is no universal correct value. A ratio near 1 indicates continuity with previous weeks, which is usually what you want mid-season; in pre-season, by contrast, going up is precisely the goal.
- Why four weeks and not another period?
- Twenty-eight days is the most commonly used period for chronic load, which is why it is adopted here. It is not a physical constant: some work uses other periods depending on the sport and calendar.
- Does it work with GPS loads instead of RPE?
- Yes. The calculation is the same with total distance, high-speed running or any other metric, as long as the same one is used in numerator and denominator.
- What if one week is zero?
- It enters the average as zero, which is correct: a week without training lowers the chronic load. If all four are zero, the ratio does not exist and the calculator returns no number.
Track this ratio without typing it in
Training Feel calculates each athlete's ratio from the sessions they already logged, and updates it week by week on its own.