1. What is the Horsepower to MPH Equation?

The horsepower to miles per hour (MPH) equation estimates a vehicle's speed based on its power-to-weight ratio. This calculation provides a theoretical maximum speed based on power and weight alone, ignoring factors like aerodynamics and drivetrain losses.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( HP \) — Engine horsepower
• \( Weight \) — Vehicle weight in pounds
• 224 — Empirical constant

Explanation: The equation shows that speed increases with the cube root of the power-to-weight ratio, meaning doubling power doesn't double speed but increases it by about 26%.

3. Importance of MPH Calculation

Details: Understanding the relationship between power, weight, and speed helps in vehicle design, performance estimation, and comparing different vehicles' potential performance.

4. Using the Calculator

Tips: Enter horsepower in hp and weight in pounds. Both values must be greater than zero for the calculation to work.

5. Frequently Asked Questions (FAQ)

Q1: Why doesn't doubling horsepower double speed?
A: Because aerodynamic drag increases with the square of speed, requiring exponentially more power to achieve higher speeds.

Q2: How accurate is this calculation?
A: It provides a theoretical maximum. Real-world speed is affected by aerodynamics, gearing, traction, and drivetrain losses.

Q3: What's a good power-to-weight ratio?
A: Sports cars typically have 0.06-0.10 hp/lb, while supercars exceed 0.15 hp/lb.

Q4: Does this work for electric vehicles?
A: Yes, but EV power delivery differs from internal combustion engines, affecting real-world performance.

Q5: Why the cube root relationship?
A: It accounts for the increasing aerodynamic drag as speed increases, requiring disproportionately more power for each mph gain.