Critical Power and W Prime Calculator
Fit the two-trial work–time critical-power model and evaluate a query power above critical power.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Fit a line through the two measured work-versus-duration points, separating slope CP from work intercept W′.
CP=(P2t2−P1t1)/(t2−t1); W′=(P1−CP)t1; modeled duration=W′/(query power−CP)
Worked example
400 W for 180 s and 300 W for 720 s give CP=266.666667 W and W′=24000 J; the model gives 288 s at 350 W.
Assumptions and input details
Longer trial must have lower mean power and produce positive CP and W′. Exactly two maximal trials cannot validate the model; fatigue, recovery, short/long duration limits and real sustainable effort are excluded. Query at/below CP has no finite duration in this model.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
SI prefixes are explicit: for example, milli means one thousandth, micro one millionth and kilo one thousand. Changing a unit changes the interpretation of the entered number.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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