Power-to-Weight Ratio Calculator
Calculate the power-to-weight ratio of a vehicle. Enter engine power (hp/kW) and weight (kg/lbs). Get PWR in hp/kg, W/kg, and more. Informational only—consult manufacturer specs.
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By Motorsport/Automotive Editor | Published: Oct 23, 2025 | Reviewed by: Motorsport/Automotive Editor
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Calculate PWR
Quick Preset Vehicles
How it works
PWR = Power (W) / Weight (kg). We convert power and weight to standard units (Watts and kilograms) and then calculate the ratio. A higher PWR generally indicates better acceleration and performance.
Conversion factors: 1 hp ≈ 745.7 W; 1 kW = 1000 W; 1 kg ≈ 2.205 lbs.
Inputs explained
- Engine Power
- The power output of the engine in horsepower (hp) or kilowatts (kW).
- Vehicle Weight
- The total weight of the vehicle in kilograms (kg) or pounds (lbs).
- Power-to-Weight Ratio
- The ratio of power to weight, expressed in various units (W/kg, hp/kg, lb/hp).
Example
Supercar: Power=700 hp (~522 kW), Weight=1500 kg
- PWR (W/kg): ≈348 W/kg
- PWR (hp/kg): ≈0.47 hp/kg
- PWR (lb/hp): ≈4.72 lb/hp
This represents excellent performance for a road-legal supercar.
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Tips & notes
- Performance metric: PWR is a key metric for comparing vehicle performance, especially for sports cars and motorcycles.
- Electric vehicles: EVs often have high PWR due to instant torque delivery from electric motors.
- Not the whole story: PWR doesn't tell the whole story; aerodynamics, gearing, tire grip, and driver skill also matter.
- F1 vs Road Cars: F1 cars have exceptional PWR (>1000 W/kg), while typical family cars have 60-120 W/kg.
- Motorcycles: Sport bikes often exceed 1000 W/kg due to their low weight.
FAQs
It varies, but >200 W/kg is considered good for a sports car. High-performance supercars can reach 300-500 W/kg, while F1 cars exceed 1000 W/kg.
Power (in Watts) divided by the vehicle's weight (in kilograms). Formula: PWR = Power (W) / Weight (kg).
It's a strong indicator of a vehicle's potential acceleration and performance. Higher PWR typically means faster acceleration (0-60 mph time).
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Both measure power-to-weight ratio but in different units. 1 hp = 745.7 W, so to convert: W/kg = hp/kg × 745.7.
Disclaimer
⚠️ Important: Informational tool based on manufacturer specifications. PWR is a performance metric but doesn't account for all real-world factors like aerodynamics, drivetrain loss, or tire grip. Consult official specs for accurate data.