The Acute Chronic Workload Calculator is a free online tool that measures the balance between what you trained this week and what your body is used to, using the acute-to-chronic workload ratio that coaches use to watch training load. It runs fully in your browser, needs no sign-up, and gives you a clear result in seconds, so you can use it at the track, in the gym, or at home without installing anything or sharing personal data.
This tool works from simple numbers you already know or can measure in one session. You enter your total training load this week and your average weekly load over the last four weeks, both in the same units, such as session load points. The tool then applies a standard formula to those numbers, so the result follows the same maths every time and two people who enter the same inputs always get the same output.
Your result shows the ratio itself, plus a simple zone label that says whether the week looks low, in the normal range, in the caution range, or high. Read the main number first, then look at the extra figures, because they often explain the result better than a single score alone. A result that looks odd usually points to a typing error or a unit mix-up, so check your inputs before you trust an extreme value.
Here is a worked example to make the maths concrete. In this example, a week of 1,000 units against a four-week average of 800 units gives a ratio of 1.25, which sits in the normal range that most coaches aim for. Try the same numbers in the tool yourself, then change one input at a time, and watch how the result moves, because that habit teaches you far more than reading a formula on its own.
How should you read the result in practice? In general, ratios near 1.0 mean this week matches your recent average, ratios below 0.8 suggest undertraining, and ratios above 1.5 suggest a sharp spike that raises injury risk. Use the result to compare your own tests over time, not to judge yourself against strangers online, because age, sport, training history, and test conditions all change what a good number looks like for you.
To get the most from this tool, follow a few simple habits. First, keep your load units the same every week, update the four-week average after each week, and plan big weeks in advance instead of adding them by surprise. Second, test under similar conditions each time, with the same warm-up and the same course or equipment, so changes in the number reflect changes in your fitness rather than changes in the test itself.
Watch out for common mistakes, because small errors can move the result a lot. The most frequent problem is mixing different load units, for example minutes one week and distance the next, because the ratio only works when every week is measured the same way. A second common problem is entering numbers in the wrong units, for example minutes instead of seconds, or pounds instead of kilograms, so double-check the unit labels on every field.
Finally, keep the limits of this tool in mind. In short, this is an educational monitoring estimate, not medical advice, and it cannot tell you whether you are injured, ill, or ready for a personal best. Used with that care, this free tool becomes a practical part of your training routine, giving you honest numbers you can track week after week without cost, accounts, or complicated software.
If you test regularly, keep a simple log with the date, your inputs, and your result, because a short written record shows progress far better than memory alone. Review the log once a month, look for slow steady improvement rather than daily jumps, and adjust your training only when a pattern holds for several weeks, not after a single unusual test.
Version en espanol: Calculadora de Carga Aguda y Crónica – Planifica y Sigue Tu Progreso