8 free tools
Cars & Motorcycles calculators
Fuel, engine and gearing calculators for riders, drivers and home mechanics. Each tool shows the formula, worked examples and sources.
Cars & MotorcyclesCompression Ratio CalculatorStatic compression ratio from bore, stroke, chamber, gasket, deck height and piston dome or dish.Cars & MotorcyclesEngine Displacement Calculator (cc)Engine size in cc, litres and cubic inches from bore, stroke and number of cylinders.Cars & MotorcyclesFuel Cost CalculatorFuel needed and cost of a trip in km or miles, L/100 km or mpg, split between passengers.Cars & MotorcyclesFuel Economy Calculator (MPG, L/100 km)Measure your real fuel consumption and convert between mpg (US/UK), L/100 km and km/L.Cars & MotorcyclesGear Ratio Speed CalculatorSpeed in every gear at any rpm from your gear ratios, final drive and tyre size, plus the rpm drop after each upshift.Cars & MotorcyclesHorsepower & Torque CalculatorConvert torque and rpm to horsepower and kW, or power and rpm back to torque.Cars & MotorcyclesTire Size CalculatorDiameter, sidewall, circumference and revolutions per km or mile from a tire size, and the speedometer error when you change sizes.Cars & MotorcyclesTwo-Stroke Oil Mix CalculatorHow much 2-stroke oil to add to petrol for 50:1, 40:1, 32:1 or any ratio.