Free tool
Critical Power and W′ Calculator.
Two short tests. Get your Critical Power, W′, and what they mean for your training and racing.
The Calculator
Run your test results through the calculator.
The two numbers
What it tells you.
What is Critical Power?
The highest steady-state power you can hold without driving anaerobic fatigue. The point where aerobic and anaerobic systems balance.
What is W′?
The fixed amount of work you can do above your Critical Power before you need to recover. Think of it as your finite battery for hard efforts.
Why it matters.
Knowing your Critical Power and W′ lets you pace events properly, structure interval training, and understand exactly what your body can sustain at race intensity. Two numbers that change how you train.
Next step
Check your event readiness. Free.
Now that you know your Critical Power, see how well your current training matches the demands of your next event. A personalised check, delivered by email. Takes 2 minutes.