How To Calculate Fuel Volume Tech Tip

The Formula

To calculate gallons per hour (GPH):
Horsepower × 0.5 ÷ 6 = GPH

Then, convert to gallons per minute (GPM) by dividing by 60:
GPH ÷ 60 = GPM

Example Calculation

Let’s say you’re working with a 350-horsepower engine:

• 350 × 0.5 = 175

• 175 ÷ 6 = 29.16 GPH

• 29.16 ÷ 60 seconds = 0.49 GPM

This gives you the expected fuel volume your engine needs. Use your fuel volume tester to compare this number with the actual reading it’s a fast, reliable way to identify fuel delivery issues.