Estimate your vehicle's 1/4 mile elapsed time (ET) and trap speed based on power and weight.
Last updated: March 2026 | By ForgeCalc Engineering
The quarter mile performance of a vehicle is primarily a function of its power-to-weight ratio. While traction, gearing, and aerodynamics play significant roles in the real world, mathematical models provide a very accurate "potential" for a given setup.
The formulas used here are standard industry benchmarks. They assume a rear-wheel-drive vehicle with decent traction on a prepared drag strip. All-wheel-drive vehicles may achieve better ETs but similar trap speeds.
*Note: These formulas use wheel horsepower (WHP), not crank horsepower.
The calculator assumes perfect conditions. Factors like wheel spin, slow shifting, high humidity, or high altitude (density altitude) will all slow you down.
It is the speed of the vehicle as it crosses the finish line. It is generally a better indicator of raw horsepower than ET, as it is less affected by the launch.
AWD cars usually 'hook' better, leading to a faster ET than predicted, but they often have more drivetrain loss, leading to a lower trap speed.
Use the 'curb weight' of the car plus the weight of the driver and any fuel/fluids. Every 100 lbs removed is typically worth about 0.1 seconds.
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