How this calculator works
A car gains kinetic energy as it accelerates. At constant power, the minimum time to a target speed is the kinetic energy gained divided by the power delivered to the road. Real cars lose power in the gearbox and differential, are limited by tire grip, and waste energy in wheelspin, so the page applies multipliers for drivetrain layout, gearbox type, tires and weather. An electric motor can deliver strong torque from rest, which is why it gets a small credit against the constant-power model. The result is an estimate, not a test-track measurement: gearing, traction control, launch technique, altitude and temperature all matter.
Formula
t = 0.5 x m x v^2 / (P x a), where m is the total mass in kg, v is the target speed in m/s, P is engine power in W and a is the combined adjustment factor. 60 mph is 26.8224 m/s and 100 km/h is 27.7778 m/s.
Worked example
A 1,500 kg sedan with a 100 kg driver and 220 kW, all-wheel drive, dual-clutch gearbox and dry performance tires has an effective power of 220,000 W. For 60 mph the ideal time is 0.5 x 1,600 x 26.8224^2 / 220,000 = 2.62 s. The sedan and electric-motor adjustments take it to about 2.56 s, and the 0-100 km/h figure is about 2.75 s.
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Frequently asked questions
Why does the estimate differ from the manufacturer figure?
Manufacturers often quote a one-foot rollout time, use a prepared surface and may publish a best-case run. This model uses a standing start, a single average power and simple loss multipliers, so a gap of a few tenths of a second is normal.
Should I enter crank power or wheel power?
Enter crankshaft power if you know it, because the gearbox and drive factors already represent the losses between the engine and the road. Entering wheel power and leaving those factors in place double-counts losses.
Can I use it for a loaded vehicle?
Yes. Add the driver, passengers and cargo to the payload, because every extra kilogram lowers the power-to-weight ratio and lengthens the time.
Does more power always give a proportionally shorter time?
At the limit of tire grip, extra power cannot be used and may even spin the wheels. The drive, tire and condition factors model that effect roughly, but a very powerful front-wheel-drive car will still be traction limited.