Free Tool · 5 min read
ACWR Calculator
Use it to see whether this week got a lot bigger than normal. Do not use it to ask a decimal whether you are about to get hurt.
This is an estimated baseline. If your normal training changes a lot from week to week, treat the ratio with less confidence.
Want to keep your numbers?
I only want this calculator answering one question
Did this week get a lot bigger than the training you normally handle?
That is it.
If the answer is yes, good to know.
Then I want to know why.
Maybe mileage jumped.
Maybe lifting volume jumped.
Maybe you raced.
Maybe every session felt good so you quietly added something to all of them.
The ratio gives you a reason to look.
Enter the last seven days like a normal person
For each day, put in how long you trained and how hard the whole session felt.
Rest day?
Zero.
Do not give the twenty minutes you spent walking around the gym looking for a bench its own workload score.
The calculator multiplies minutes by session effort.
Sixty minutes at an effort of 5 gives you 300 load units.
Those units are arbitrary.
That is fine.
We are using them to compare training, not pretending 300 is a direct measurement of fatigue in your bloodstream.
Then tell it what a normal week looks like
This is the part people can accidentally rig.
If your normal week is four training days around 50 minutes, do not enter the hardest seven-day stretch you have ever survived because you want today's ratio to look nicer.
Use normal.
The calculator needs a believable baseline more than it needs a flattering one.
This manual tool estimates that baseline from frequency, duration, and effort.
That makes it easy to use.
It also means the baseline is rough.
Keep that in mind.
The labels describe workload. They do not diagnose anything.
Below baseline means the recent week is lighter than the estimate.
Near baseline means it is in roughly the same neighborhood.
Above baseline means the week got meaningfully bigger.
Large spike means it got a lot bigger.
I deliberately do not call those safe, unsafe, low-risk, or high-risk zones.
The calculator does not know enough to make those claims.
The old sweet-spot idea is way too clean for me
You will still see ACWR graphics with a beautiful green zone in the middle.
Then the number crosses a line and suddenly turns red.
Looks great.
Training is not that precise.
A ratio of 1.29 and 1.31 are not different species of workout.
The result also depends on how the load and baseline are calculated.
I care about obvious jumps.
I care a lot less about tiny moves across a color boundary.
What I would do after a high result
Ask why the week got bigger.
Then look at the athlete.
Are easy runs still easy?
Are normal warm-up weights moving normally?
How is sleep?
Is soreness hanging around?
Was the harder week planned?
Did you just race?
A high ratio with normal performance and recovery is a different situation from a high ratio while everything else is starting to slide.
Hybrid training is why I keep more than one workload stream
A combined number can hide where the stress came from.
Running goes way up.
Lifting comes down.
Total looks normal.
Your calves may disagree.
That is why Mass in Motion tracks running load, lifting load, and the combined picture instead of asking one ratio to explain the whole week.
If you want the deeper explanation, read ACWR and Training Load. If you want the shorter walkthrough, use How to Use the ACWR Calculator.