Our Automotive Calculators help drivers, enthusiasts, mechanics, and engineers quickly calculate engine performance, convert power and torque units, compare vehicle specifications, and analyse real-world performance. Whether you're tuning a sports car, comparing manufacturer specifications, or simply curious about your vehicle's performance, these free online tools provide fast and accurate results.
Calculate HP per tonne and kW per tonne to compare the performance of cars, motorcycles, and electric vehicles.
Convert instantly between Horsepower (HP), Metric Horsepower (PS), and Kilowatts (kW).
Convert torque between Newton metres (Nm), pound-feet (lb-ft), pound-inches (lb-in), and kilogram-metres (kg·m).
Compare tyre sizes, rolling diameter, sidewall height, circumference, and speedometer difference.
Compare wheel width, offset (ET), and tyre fitment to see inner and outer clearance changes.
Calculate gear ratios, final drive ratios, wheel speed, and torque multiplication for any drivetrain.
Automotive calculators are designed to simplify common vehicle-related calculations that would otherwise require manual formulas or multiple conversion tables. They help compare engines from different countries, understand manufacturer specifications, estimate vehicle performance, and make technical data easier to interpret.
Our calculators support the most common automotive measurement systems used across Europe, the United Kingdom, North America, and international motorsport.
These calculators are useful for a wide range of automotive tasks, including:
Different countries publish engine specifications using different units. German manufacturers commonly quote power in PS, North American publications often use HP, while electric vehicles usually list power in kW. Likewise, torque may be shown in Nm, lb-ft, or other units depending on the source.
These calculators eliminate the need to remember conversion factors and provide accurate results instantly.
A performance car produces 650 PS.
An engine produces 850 Nm.
Vehicle Power:
500 HP
Vehicle Weight:
1,600 kg
Why do European manufacturers use PS?
PS (Pferdestärke) is the traditional metric horsepower used throughout much of Europe and is still quoted by manufacturers such as Mercedes-Benz, BMW, Audi, Porsche, and Volkswagen.
Is HP the same as BHP?
For everyday automotive use, HP and BHP are effectively the same. The numerical difference is extremely small and is generally ignored in vehicle specifications.
What is considered a good power-to-weight ratio?
Around 150 HP per tonne offers lively everyday performance, while sports cars usually exceed 250 HP per tonne. Vehicles above 500 HP per tonne enter hypercar territory.
Are these calculators suitable for motorcycles?
Yes. The Power Converter, Torque Converter, and Power-to-Weight Calculator all work for motorcycles, cars, vans, trucks, race cars, and electric vehicles.
Simple Calculator is an independent family-run project focused on creating practical online tools that are fast, accurate, and easy to use. Every automotive calculator is built using recognised engineering conversion factors and is designed to work perfectly on desktop and mobile devices.
You may also find our Fuel Cost Calculator, Mileage Calculator, EV vs Petrol Running Cost Calculator, Unit Converters, and Financial Calculators useful.
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Last Updated: August 2026