Engine Hours to Miles Calculator

How it works

driving hours = engine hours × (1 − idle share) · distance = driving hours × average moving speed · wear-equivalent = distance + idle hours × 33 mi (53 km) · average speed = odometer ÷ engine hours

Engine hour meters count time with the engine running, whether the vehicle is moving or not, so converting hours to distance needs an average speed. For a road vehicle, distance is the moving hours times the average moving speed; a city car averages 25–35 km/h, mixed driving 40–50 km/h. Idling adds hours but no distance, yet still wears the engine: Ford's guidance for its police vehicles equates one hour of idling to about 33 miles (53 km) of driving, which is why fleet buyers look at both numbers. If you know the odometer reading, dividing it by the hours gives the vehicle's true average (shown overall and over moving hours only).

Worked example

1,500 engine hours with 20% idling and a 40 km/h moving average: 1,200 driving hours × 40 = 48,000 km driven; adding 300 idle hours × 53.1 km gives a wear-equivalent of 63,930 km.

Sources: Ford Pro — Police Interceptor engine idle hour meter

Frequently asked questions