Free tools
Outboard & boat calculators
Five calculators for the questions we get asked most before an order: how much power a hull needs, which propeller to fit, what fuel will cost, which shaft length fits the transom, and how much oil a two-stroke mix takes. Every recommendation links straight to matching motors from our 2,306 listings.
Outboard horsepower calculator
Enter your boat's length, weight and use to get a recommended horsepower range, plus the motors we stock in that range.
Boat propeller & speed calculator
Calculate boat speed from RPM, gear ratio, prop pitch and slip — or find the pitch needed to reach a target speed.
Outboard fuel consumption calculator
Estimate litres or gallons per hour and running cost from horsepower, throttle setting and fuel price.
Outboard shaft length calculator
Measure your transom and get the correct shaft length: 15in short, 20in long, 25in XL or 30in XXL.
Two-stroke fuel mix calculator
Enter fuel volume and mix ratio to get the exact oil quantity in millilitres or fluid ounces.