How to use this calculator
Choose mass and speed units, then enter the vehicle mass including occupants and cargo. Enter a rolling resistance coefficient appropriate to the tires and operating conditions, or use several clearly labeled assumptions for a sensitivity comparison. The tool estimates the combined tire rolling component for the whole vehicle; do not multiply the result by the number of tires.
Assumes steady rolling on level ground, constant Crr, and total normal load equal to weight. It excludes aerodynamic lift/downforce, road slope, acceleration, drivetrain losses, auxiliaries and tire slip. It does not model starting resistance at standstill. The result is mechanical energy at the wheels, not battery consumption, fuel use, a tire rating or a recommended inflation pressure.
The formula
A worked example
For a hypothetical 1,500 kg vehicle, Crr = 0.01 and 100 km/h, rolling force is 0.01 × 1,500 × 9.80665 = 147.10 N. Speed is 27.7778 m/s, giving 4.086 kW of mechanical power. Over 100 km the rolling component requires 4.086 kWh. At 50 km/h the power halves to 2.043 kW, but the same distance takes twice as long, so rolling energy per 100 km stays unchanged in this constant-coefficient model.
Coefficient sensitivity at 1,500 kg and 100 km/h
Hypothetical assumptions for comparison, not recommended tire coefficients.
| Crr (decimal) | Rolling force (N) | Mechanical power (kW) |
|---|---|---|
| 0.008 | 117.68 | 3.27 |
| 0.010 | 147.10 | 4.09 |
| 0.012 | 176.52 | 4.90 |
Common questions
Where should I get the coefficient?
Use applicable measured or manufacturer test data with its conditions and units. A value for a different load, temperature, pressure or surface may not represent your trip. The default 0.01 is an example, not a verified value for your tires. Tire dimensions alone cannot establish Crr.
Is Crr the same as tire grip?
No. This coefficient describes resistance to rolling. It is not the traction coefficient used to estimate braking, cornering or wheelspin limits. Do not use it to assess stopping distance.
Why does speed change power but not energy per distance?
With an unchanged coefficient and load, this model gives constant force. Power is force times speed, whereas work over a fixed distance is force times distance. Real tire behavior may require a coefficient that varies with speed and conditions.
Can I use a value quoted in N/kN?
For a rolling resistance coefficient expressed as force divided by normal load, divide an N/kN value by 1,000 to obtain the dimensionless decimal. For example, 10 N/kN corresponds to 0.010. Confirm that the source is reporting that ratio and that its test conditions apply.
Should I add a force for each tire?
This tool already uses total vehicle weight and one effective coefficient for all tires. For mixed coefficients, calculate each tire or axle force from its own supported mass and add those forces instead.
Can I add this to the drag and hill results?
They describe separate mechanical road-load components, but only combine results calculated for consistent conditions. This page assumes level ground; a slope changes normal load. A total battery or fuel forecast still requires other loads and conversion efficiencies.
Does a lower result prove a tire will save a particular amount of fuel?
No. Fuel use depends on the full vehicle and operating conditions. This calculation isolates one modeled component and cannot establish a measured fuel-economy improvement or tire compatibility.
Sources & calculation method
MathWorks: Rolling Resistance documents the constant-coefficient relationship between rolling force, normal load and resistance coefficient. Its simulation also provides speed-transition and pressure/speed-dependent models. This simpler calculator uses the steady-rolling constant-coefficient relationship, with level-ground normal load approximated by vehicle weight; it does not reproduce those simulation models. The power and energy results follow P = Fv and E = Fd.
Reference accessed September 19, 2026. Examples are original hypothetical calculations. The source supports the method, not an endorsement or independent professional review.
Formula examples and input validation have automated checks. This page has not received an independent automotive professional review. Read our review standards.