A quarter mile calculator estimates your vehicle's elapsed time (ET) and trap speed for a quarter-mile drag strip run based on weight and horsepower. Using the well-known Roger Huntington formula, this tool helps car enthusiasts, drag racers, and tuners predict performance before hitting the strip. Adjust for drivetrain losses, simulate modifications, and compare two vehicles side by side.
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Click a preset to fill the active vehicle inputs.
Vehicle Specs
Power Details
What-If Modification Calculator
Estimates Only
These calculations use empirical formulas that provide approximations. Real quarter-mile results depend heavily on traction, tire compound, launch technique, altitude, temperature, humidity, vehicle aerodynamics, and driver skill. Use these numbers as a starting reference, not a guarantee.
Vehicle A
Vehicle B
Head-to-Head Comparison
| Metric | Vehicle A | Vehicle B | Difference |
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These are estimated values based on empirical formulas. Real-world quarter-mile results depend on traction, altitude, temperature, driver skill, tire compound, and many other factors.
How to Use the Quarter Mile Calculator
Whether you are preparing for a trip to the drag strip or simply curious about your car's potential, this quarter mile calculator gives you a quick estimate of your elapsed time and trap speed. It uses the Roger Huntington formula, a well-established empirical equation that has been relied upon by the automotive community for decades. While no calculator can replace an actual time slip, these estimates provide a solid baseline for comparing vehicles, evaluating modifications, and setting realistic expectations.
Step 1: Enter Your Vehicle's Weight and Horsepower
Start by entering your vehicle's curb weight in pounds and its engine horsepower. Curb weight is the total weight of the vehicle with all fluids and a full tank of fuel, but without passengers or cargo. You can find this in your owner's manual or on the manufacturer's specification sheet. For horsepower, use the rated crank horsepower from the factory, or your dyno-tested figure if you have one.
Step 2: Select Your Drivetrain Type
Choose your drivetrain configuration to account for power lost between the engine and the wheels. Front-wheel drive (FWD) and rear-wheel drive (RWD) vehicles typically lose about 15% of crank horsepower through the transmission and differential, while all-wheel drive (AWD) systems lose roughly 20% due to additional drivetrain components. Select "No Drivetrain Loss" if you already have wheel horsepower numbers from a dyno.
Step 3: Review Your Quarter Mile Estimates
Click "Calculate Quarter Mile" to see your estimated elapsed time (ET), trap speed, 0-60 mph time, and 60-foot time. The ET tells you how long the full quarter-mile pass would take, while the trap speed shows how fast you would be going at the finish line. The 0-60 estimate and 60-foot time give additional context about launch performance.
Step 4: Simulate Modifications
Use the "What-If Modification Calculator" to see how adding horsepower or reducing weight would affect your quarter-mile time. Enter a hypothetical HP gain (from an intake, exhaust, tune, or turbo kit) or weight reduction (removing seats, lighter wheels, carbon fiber parts) and the tool instantly shows the new ET compared to your baseline. This helps you decide which modifications give the best bang for the buck.
Step 5: Compare Two Vehicles
Switch to "Compare Two Vehicles" mode to enter specs for two different cars and see them side by side. The comparison table shows ET, trap speed, 0-60, and power-to-weight ratio for both vehicles, along with the exact differences. A winner banner highlights which vehicle has the faster quarter mile time. This is great for settling friendly debates or evaluating a potential purchase against your current car.
Understanding the Formulas
The Huntington formula calculates ET as 5.825 x (weight / HP) ^ (1/3) and trap speed as 234 x (HP / weight) ^ (1/3). The 0-60 estimate is approximately 47% of the ET, and the 60-foot time is estimated at roughly 26% of the ET. All calculations happen instantly in your browser with no data sent to any server.
Frequently Asked Questions
Is this quarter mile calculator really free?
Yes, the quarter mile calculator is completely free with no signup or account needed. All calculations run locally in your browser, so you can estimate as many vehicles as you want without any limits.
Is my data safe when using this tool?
Absolutely. Everything is calculated in your browser using JavaScript. No vehicle data or personal information is transmitted or stored on any server. Your privacy is fully protected.
How accurate is the quarter mile ET formula?
The Roger Huntington formula (ET = 5.825 x (weight/HP)^(1/3)) is a well-known empirical approximation used in the automotive community. It is reasonably accurate for naturally aspirated vehicles but real-world results depend on traction, tire grip, altitude, temperature, and driver skill.
What is drivetrain loss and how does it affect the calculation?
Drivetrain loss accounts for the power lost between the engine and the wheels through the transmission, driveshaft, and differential. Front-wheel drive and rear-wheel drive vehicles typically lose about 15% of engine power, while all-wheel drive vehicles lose roughly 20%. The calculator applies this to give wheel horsepower estimates.
What is trap speed in a quarter mile run?
Trap speed is the vehicle's speed measured at the finish line (the speed trap) at the end of a quarter-mile run. It reflects the car's power-to-weight ratio more than ET does, because ET is heavily influenced by launch and traction. Higher trap speeds indicate more available power.
How is the 0-60 time estimated from the quarter mile ET?
The 0-60 mph time is approximated as roughly 47% of the quarter-mile elapsed time (ET x 0.47). This is a commonly used rule of thumb in automotive performance estimation, though actual 0-60 times vary significantly based on gearing, launch technique, and traction.
Can I use this calculator for turbocharged or modified cars?
Yes, but keep in mind the Huntington formula was derived from naturally aspirated vehicles. Turbocharged and heavily modified cars may perform better or worse than predicted due to factors like boost lag, traction limitations, and power delivery characteristics. Use the modification calculator to see estimated improvements from added horsepower.
What does the 60-foot time represent?
The 60-foot time measures how long it takes the vehicle to cover the first 60 feet from a standing start. It is a critical measure of launch performance and traction. A good 60-foot time on a street tire is around 2.0-2.2 seconds, while drag radials can achieve 1.5-1.7 seconds.