Power-to-Weight Ratio Calculator
Use our power-to-weight ratio calculator to calculate power to weight for a car, bike, or any vehicle. Includes power-to-weight ratio explained, the power-to-weight ratio formula, how to calculate power to weight step by step, and what is a good power-to-weight ratio (general guidance).
Power-to-Weight Ratio Explained
Power-to-weight ratio measures how much power something has relative to how much it weighs. For vehicles, it’s a quick way to compare performance potential—more power and less weight generally means faster acceleration.
You’ll see it expressed in different units such as hp per lb, hp per kg, kW per kg, or the inverse form like lb per hp (weight per unit of power).
A power-to-weight ratio doesn’t capture everything (traction, gearing, aerodynamics, torque curve), but it’s a useful headline metric when comparing vehicles.
Power-to-Weight Ratio Formula
Divide power by weight (or weight by power if you prefer the inverse).
Example units: hp/lb, hp/kg, or kW/kg.
Example units: lb/hp or kg/kW (lower is better).
More hp/lb generally means stronger acceleration potential.
Lower lb/hp is generally better.
How to Calculate Power-to-Weight Ratio
- 1
Enter power (horsepower or kilowatts).
- 2
Enter weight (pounds or kilograms).
- 3
Choose the output format you want (power/weight or weight/power).
- 4
The calculator divides power by weight (or weight by power) and shows your power-to-weight ratio.
Frequently Asked Questions
Power-to-weight ratio is power divided by weight. It’s used to compare performance potential—higher power with lower weight usually improves acceleration.
It’s a simple way to quantify how much power is available to move each unit of weight. With similar traction and gearing, higher power-to-weight generally means quicker acceleration.
Divide power by weight. Example: 200 hp ÷ 2,500 lb = 0.08 hp/lb. Or use the inverse: 2,500 lb ÷ 200 hp = 12.5 lb/hp.
Use the power rating you’re comparing (commonly engine horsepower). For consistent comparisons, make sure you’re comparing similar measurements across vehicles (same unit system and similar rating conventions).
It’s a performance metric that indicates how much power is available relative to weight. Higher values (power/weight) or lower values (weight/power) generally indicate better acceleration potential.
“Good” depends on the category (economy car vs sports car vs motorcycle). A helpful approach is comparing your ratio to similar vehicles in the same class using the same units.