Drag Racing ET Calculator

Estimate quarter-mile elapsed time and trap speed from vehicle weight and horsepower. Accounts for altitude and temperature effects on engine performance.

Inputs

Vehicle Weight

lbs

Horsepower

Track Altitude

Air Temperature

°F

Tab to move between fields

Results

Quarter Mile ET

12.15 sec

Quarter Mile MPH112.2 mph

60-Foot Time2.19 sec

Eighth Mile ET7.68 sec

Density Altitude1,160 ft

How to Use This Calculator

Enter Vehicle Weight, Horsepower, and Track Altitude.
Set Air Temperature.
Review the Quarter Mile ET (sec) result.
Use Quarter Mile MPH (mph) and 60-Foot Time (sec) to inform your decision.

How the result changes with Horsepower

Horsepower	Quarter Mile ET
545	10.96 sec
1,783	7.38 sec
3,268	6.03 sec
4,505	5.42 sec

What each input means

Vehicle Weight: Total vehicle weight including driver and fluids in pounds. Weigh with a full tank and driver aboard.
Horsepower: Wheel horsepower (WHP) from a dyno pull. If you only have crank HP, multiply by 0.85 for a rough WHP estimate.
Track Altitude: Elevation of the drag strip above sea level in feet. Higher altitude reduces air density and engine power.
Air Temperature: Ambient air temperature in Fahrenheit. Cooler air is denser and produces more power.

What each result means

Quarter Mile ET: Estimated elapsed time for the quarter mile using the Huntington formula.
Quarter Mile MPH: Estimated trap speed at the end of the quarter mile.
60-Foot Time: Estimated 60-foot time. Actual time depends heavily on launch technique and traction.
Eighth Mile ET: Estimated eighth-mile elapsed time (approx. 63.2% of quarter mile ET).
Density Altitude: Effective altitude accounting for temperature. Higher values mean less power.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Vehicle Weight = 3500, Horsepower = 400, Track Altitude = 500, Air Temperature = 70 = 4 input(s) provided
Calculate Quarter Mile ET
Quarter Mile ET
12.146 = 12.146
Calculate Quarter Mile MPH
Quarter Mile MPH
112.2 = 112.2
Calculate 60-Foot Time
60-Foot Time
2.186 = 2.186

Engine last updated July 26, 2026. Checked against 2 independently-derived tests — how we verify calculators.

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