Convert watt losses: cr & cwA/CdA calculator
Rolling or aero losses are often given as a watt value at a specific speed—for example from tests, magazines, or manufacturer data. These two mini calculators help you derive the underlying coefficients: cr for tire rolling resistance and cwA/CdA for aerodynamic drag.
This is especially useful if you want to compare values across sources or use them in simulations/training planning: watts always depend on speed, whereas cr and cwA/CdA are (under the same test conditions) the more comparable metrics.
Next step with cr & cwA/CdA: In the Bike Calculator you can calculate the resulting speed (or the required watts).
Open Bike Calculator
- Rolling calculator: calculates cr from rolling watts, speed, and weight (optionally specified per wheel).
- Aero calculator: calculates cwA/CdA from aero watts, speed, and air density ρ.