Rolling Resistance Calculator: Formula, Examples & Usage Guide
Rolling resistance is a fundamental force in physics and engineering that affects every wheeled vehicle on Earth — from a child's bicycle to a fully loaded semi-truck. Understanding rolling resistance is essential for optimising fuel efficiency, extending tire life, improving electric vehicle range, and designing better roads and rail systems. This free bulk rolling resistance calculator removes the friction from your calculations, delivering instant, accurate results for any number of vehicles or scenarios.
What Is Rolling Resistance?
Rolling resistance, sometimes called rolling friction or rolling drag, is the resistive force that opposes the motion of a body rolling on a surface. Unlike sliding friction, rolling resistance arises mainly from the repeated deformation of the contact zone — the tire flexes as it rolls, generating heat energy that is lost to the environment. Secondary contributors include surface micro-slip at the contact patch, air resistance inside the tire, and bearing losses.
The Rolling Resistance Formula
The standard engineering formula for rolling resistance force is:
FormulaF = Crr × m × g × cos(θ)
Where F is the rolling resistance force in Newtons (N), Crr is the dimensionless rolling resistance coefficient, m is the total mass of the vehicle or object in kilograms, g is gravitational acceleration (9.80665 m/s² on Earth's surface), and θ is the slope angle in degrees. On level ground, cos(0°) = 1, so the formula simplifies to F = Crr × m × g.
Rolling Resistance Power Loss
When a vehicle is moving, rolling resistance continuously consumes energy. The power dissipated is calculated as:
Power FormulaP = F_rr × v
Where P is the power loss in Watts and v is velocity in metres per second. For a typical passenger car at 100 km/h (27.78 m/s) with a rolling resistance force of 176 N, the power loss is approximately 4,889 W — nearly 5 kW consumed purely by rolling resistance, highlighting why Crr matters for fuel economy and EV range.
Typical Rolling Resistance Coefficient (Crr) Values
The Crr value varies significantly depending on tire type, inflation pressure, road surface, and vehicle speed. Common reference values include: car tires on asphalt (0.010–0.015), truck tires on highway (0.006–0.010), bicycle tires on tarmac (0.002–0.008), railway steel wheels on rail (0.001–0.002), and off-road tires on packed dirt (0.020–0.040). Low rolling resistance tires for electric vehicles can achieve Crr values as low as 0.007.
Worked Examples
Example 1 — Passenger CarMass: 1,500 kg · Crr: 0.012 · g: 9.80665 m/s² · Slope: 0°
F = 0.012 × 1500 × 9.80665 = 176.52 N
At 100 km/h (27.78 m/s): P = 176.52 × 27.78 = 4,903 W ≈ 4.9 kW
Example 2 — BicycleMass: 90 kg (rider + bike) · Crr: 0.005 · g: 9.80665 m/s² · Slope: 2°
Normal Force = 90 × 9.80665 × cos(2°) = 882.5 N
F = 0.005 × 882.5 = 4.41 N · At 25 km/h (6.94 m/s): P = 30.6 W
Example 3 — Loaded TruckMass: 25,000 kg · Crr: 0.008 · g: 9.80665 m/s²
F = 0.008 × 25000 × 9.80665 = 1,961.3 N
At 90 km/h (25 m/s): P = 49,033 W ≈ 49 kW
Practical Applications
Rolling resistance calculations are used across many industries. Automotive engineers use Crr data to improve fuel economy ratings and meet emissions targets. Electric vehicle manufacturers optimise Crr alongside aerodynamic drag to maximise driving range. Railway operators use rolling resistance models to plan train schedules and calculate energy consumption. Sports scientists analyse rolling resistance for competitive cycling, speed skating, and wheelchair racing. Use this bulk calculator to run fleet-wide scenarios, compare tire options, or validate simulations instantly.