Calculate 1 4 Mile Time

1/4 Mile Time Calculator

Predict your vehicle's drag strip performance based on the power-to-weight ratio.

Include driver weight for accuracy.

Net flywheel horsepower is standard.

Estimated Results

Elapsed Time (ET)

0.00

Seconds

Trap Speed

0.00

MPH

function calculateQuarterMile() { var weight = parseFloat(document.getElementById('vehicleWeight').value); var hp = parseFloat(document.getElementById('horsepower').value); var resultsDiv = document.getElementById('resultsArea'); var etDisplay = document.getElementById('etDisplay'); var speedDisplay = document.getElementById('speedDisplay'); if (isNaN(weight) || isNaN(hp) || weight <= 0 || hp <= 0) { alert("Please enter valid positive numbers for both weight and horsepower."); return; } // Standard drag racing formulas // ET = 5.825 * cuberoot(weight / hp) // Speed = 234 * cuberoot(hp / weight) var et = 5.825 * Math.pow((weight / hp), 1/3); var speed = 234 * Math.pow((hp / weight), 1/3); etDisplay.innerText = et.toFixed(2); speedDisplay.innerText = speed.toFixed(2); resultsDiv.style.display = 'block'; }

---

How to Predict 1/4 Mile Performance

Understanding the physics behind a 1/4 mile run is essential for any drag racing enthusiast or automotive tuner. The two primary factors that determine how fast a car can travel 1,320 feet from a standing start are its curb weight and its horsepower. This relationship is known as the power-to-weight ratio.

The Physics of Drag Racing

While variables like traction, gear ratios, and weather conditions (density altitude) play a role, the theoretical limit of a vehicle is defined by its ability to move its mass using its power output. We use the industry-standard formulas developed through decades of track data:

• Elapsed Time (ET): This measures how many seconds it takes to cover the distance. It is heavily influenced by the initial launch and the vehicle's weight.
• Trap Speed: This is the speed of the vehicle as it crosses the finish line. Interestingly, trap speed is often a better indicator of a car's raw horsepower than the ET, as it is less affected by poor traction at the start.

Examples of 1/4 Mile Calculations

To see how weight and power interact, look at these realistic scenarios:

Vehicle Type	Weight (lbs)	HP	Est. ET
Modern Muscle Car	3,800	485	11.55s
Lightweight Sports Car	2,400	200	13.33s
Modified Tuner	3,000	600	9.96s

Factors That Influence Your Real-World Time

It is important to remember that these calculations represent a "perfect" run with ideal traction. In the real world, several factors may result in slower times:

1. The "60-Foot" Time: This is the time it takes to cover the first 60 feet. If your tires spin, your 60-foot time increases, which can ruin your overall ET even if you have massive horsepower.
2. Transmission Type: Modern dual-clutch transmissions (DCT) or high-performance automatics usually shift faster and more consistently than manuals.
3. Elevation: Higher altitudes have "thinner" air, meaning less oxygen for the engine, which significantly reduces horsepower unless you are using a turbocharger or supercharger.
4. Tire Compound: Slick tires or drag radials allow for much harder launches than standard street tires.

Pro Tip: When using the calculator, make sure to add the driver's weight and the weight of the fuel to the vehicle's curb weight for the most accurate prediction possible.