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Power-to-Weight Ratio Formula:
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Power-to-weight ratio (PWR) is a measurement of actual performance for any vehicle or machine. It is calculated by dividing the power output by the weight (or mass) of the vehicle, typically expressed in kilowatts per tonne (kW/tonne).
The calculator uses the Power-to-Weight Ratio formula:
Where:
Explanation: The formula converts weight from kilograms to tonnes (by dividing by 1,000) and then divides the power by this value to get the power-to-weight ratio in kW/tonne.
Details: Power-to-weight ratio is a crucial performance metric in automotive engineering, motorsports, and machinery design. A higher ratio indicates better acceleration and performance capabilities. It's particularly important for comparing vehicles of different sizes and weights.
Tips: Enter power in kilowatts (kW) and weight in kilograms (kg). Both values must be positive numbers. The calculator will automatically compute the power-to-weight ratio in kW/tonne.
Q1: Why is power-to-weight ratio important?
A: It provides a standardized way to compare performance across different vehicles and machines, accounting for both power output and weight.
Q2: What is a good power-to-weight ratio?
A: This varies by application. For passenger cars, 50-100 kW/tonne is typical. High-performance sports cars may exceed 200 kW/tonne, while racing cars can reach 500+ kW/tonne.
Q3: Can I use horsepower instead of kilowatts?
A: Yes, but you'll need to convert horsepower to kilowatts first (1 kW ≈ 1.341 horsepower) or use a different formula specifically for horsepower per tonne.
Q4: How does weight affect vehicle performance?
A: Lower weight with the same power results in better acceleration, braking, and handling. This is why lightweight materials are prized in performance applications.
Q5: Is this calculation used in electric vehicles?
A: Yes, power-to-weight ratio is equally important for electric vehicles and is calculated the same way using the motor's power output.