Power-to-Weight Ratio Calculator

Power-to-weight ratio is your engine's power divided by your vehicle's weight — most often expressed as horsepower per U.S. ton (2,000 lb): divide horsepower by weight in pounds, then multiply by 2,000.

The Formula Explained

The core formula is simple: hp/ton = horsepower ÷ (weight in pounds ÷ 2,000). Dividing by 2,000 first converts weight into tons, so the result lands in a readable range — typically double or triple digits — instead of the tiny decimal you'd get from horsepower per pound alone. Some sources use horsepower per 1,000 lb instead, which is the same idea at a different scale (just divide by 1,000 rather than 2,000), and the metric world expresses the same concept as kilowatts per tonne. All three describe the same relationship: more power per unit of weight means the engine has less mass to accelerate for every unit of force it produces.

A Real Example: 2023 Corvette Stingray

Take the 2023 Chevrolet Corvette Stingray coupe: a 490 hp 6.2L V8 in a car with a curb weight of 3,366 lb. Divide 3,366 by 2,000 to get 1.683 tons, then divide 490 hp by 1.683 tons for a power-to-weight ratio of about 291 hp per ton. Expressed the other common way, that's roughly 146 hp per 1,000 lb, or about 239 kW per tonne. For context, an average family sedan usually lands closer to 100-150 hp per ton, so the Stingray's 291 puts it well into the high-performance range shared by proper sports cars.

Common Questions

What counts as a "good" power-to-weight ratio? Roughly speaking, under 100 hp/ton is typical of economy cars, 100-150 is an average modern sedan, 150-250 is a sporty car, and 250-400 is firmly in high-performance territory — supercars and hypercars routinely clear 400-500+.

Does it matter whether I use hp/ton or hp per 1,000 lb? No — they're the same ratio at two different scales, and this calculator shows both alongside the metric kW/tonne figure so you can quote whichever your source material uses.

Does this account for drivetrain losses? No. The horsepower you enter is whatever figure you're working from (usually a manufacturer's crank rating), and this calculator doesn't subtract for losses through the transmission and drivetrain on the way to the wheels — a dyno-measured wheel horsepower figure will always give a lower, more conservative ratio than the advertised crank figure.

What This Number Doesn't Capture

Power-to-weight ratio is a useful shorthand for comparing how much muscle a vehicle has relative to its bulk, but it's a proxy, not a lap time. It says nothing about aerodynamic drag, tire grip, gearing, weight distribution, or how efficiently a chassis can put that power down without wheelspin — two cars with an identical ratio can post very different 0-60 times once those factors come into play. Treat it as a quick way to compare engines and vehicles on paper, not a substitute for a real-world performance test.