Power to Weight Ratio Calculator

Calculate performance metrics for cars, cycling, and weightlifting. Enter power and weight to instantly see 0-60 estimates, Watts/kg for cyclists, and legal checks for LAMS/P-Platers. Supports HP per ton, kW per tonne, and more.

Enter Performance Stats:

Power:

Weight / Mass:

Performance Ratios:

Watts per Kg (Cycling/Rowing)

1000.00

kW per Tonne (LAMS/P-Plater)

1000.00

MegaWatt per Kilogram

0.00100

Horsepower per Kilogram

1.341

Horsepower per Pound (Drag Racing)

0.608

Horsepower per Ton (Cars)

1341.0

How to Calculate Power to Weight Ratio

Input the power (HP, kW, Watts) and weight (kg, lbs). This works for cars, motorcycles (LAMS), and athletes (cycling FTP).

Choose your preferred units. The calculator automatically converts HP to kW or lbs to kg for accurate ratio comparison.

View results in standard formats like "HP per Ton" (for 0-60 estimates) or "Watts/kg" (for cycling performance).

Click any result card to set a target ratio (e.g., '150 kW/t' for LAMS compliance) and see how much power you need.

Power to Weight Ratio Benchmark Chart

Compare your ratio against common vehicle classes. This chart helps estimate 0-60 mph times and checks against P-Plater/LAMS limits (130 kW/t).

Vehicle Category	Power Ratio	Watts/kg	Est. 0-60 mph
Economy Car	60 - 75 kW/t	60 - 75 W/kg	10.0s +
P-Plate / LAMS Limit	130 kW/t	130 W/kg	7.0s - 8.0s
Sporty Hatch	135 - 165 kW/t	150 W/kg	6.0s - 7.0s
Sports Car	185 - 260 kW/t	220 W/kg	4.0s - 5.5s
Supercar	370 - 485 kW/t	400 W/kg	2.8s - 3.5s
Formula 1 / Hypercar	735+ kW/t	750+ W/kg	< 2.5s

The Physics of Speed

Why Power to Weight Ratio is the ultimate equalizer in performance.

At its core, acceleration is governed by Newton's Second Law: F = ma (Force equals Mass times Acceleration). Rearranging this formula gives us a = F / m.

This simple equation proves that to accelerate faster, you have two options: increase the FORCE (Power) or decrease the MASS (Weight). This is why a lightweight Lotus Elise with only 200hp can keep up with a heavy 400hp muscle car on a twisty track. The calculator above helps you quantify this relationship instantly.

Smart Buying Guide: What Ratio Do You Need?

When shopping for a car, horsepower numbers can be misleading. A heavy SUV with 300hp will feel much slower than a compact sedan with the same power. Use our benchmarks to find your sweet spot:

Daily Commuter (> 10 kg/hp): Prioritizes fuel economy and comfort over speed. Adequate for highway merging but won't press you into your seat.
Spirited Driving (5 - 8 kg/hp): The fun zone. Most sports sedans and hot hatches fall here. Responsive, agile, and powerful enough to thrill.

Pro Tip

"Always check the curb weight, not just the engine power. A 200hp car weighing 1,000kg is significantly faster than a 300hp car weighing 1,800kg."

Improving Your Ratio: Tune or Train?

For Vehicle Owners

Adding horsepower is expensive. Reducing weight is often free.

Remove unnecessary seats or cargo.
Switch to lighter wheels and tires.
Use carbon fiber components for body panels.

For Cyclists & Athletes

Watts per Kilogram (W/kg) is the golden standard for climbing.

Focus on High-Intensity Interval Training (HIIT).
Maintain muscle mass while reducing body fat.
Optimize gear weight (lighter bike frame/shoes).