About This Calculator
This calculator estimates the power-to-weight ratio of a vehicle, machine, or athlete by dividing the total power output by weight. It is commonly used to assess performance in motorsports, cycling, and aviation.
How It Works
- Enter the total power output of the system and select its unit.
- Enter the weight and select its unit.
- The calculator converts all units to watts and kilograms, then computes the ratio in watts per kilogram (W/kg).
- The higher the ratio, the greater the performance potential per unit of weight.
Frequently Asked Questions
What is power-to-weight ratio?
It's the amount of power available per unit of weight, usually measured in watts per kilogram (W/kg). It indicates how efficiently a system converts power into motion relative to its weight.
Why is W/kg used instead of hp/ton?
W/kg is the SI standard and more precise. However, hp/ton is also common in automotive contexts and can be added as an alternate output.
Can I use it for cyclists or aircraft?
Yes. Cyclists often use W/kg to assess climbing ability. Aircraft and drones use it to evaluate thrust performance relative to mass.
What if I enter values in hp and lb?
The calculator will automatically convert horsepower to watts and pounds to kilograms before calculating the result.
Is a higher power-to-weight ratio always better?
Generally yes, for speed and acceleration. But in real-world applications, factors like aerodynamics, traction, and gearing also matter.