Gas Mileage Calculator - Calculator See


Gas Mileage Calculator

Calculate vehicle fuel economy in Miles Per Gallon (MPG) or Liters per 100km (L/100km) based on odometer trip distance and gas tank fill-up volume.

Calculator Inputs

miles
Odometer miles driven since last fill-up.
gal
Gallons required to refill tank.
$
Local fuel price.

Calculated Results

Vehicle Fuel Economy
30.00 MPG (7.84 L/100km)
Liters per 100 km 7.84 L/100km
Kilometers per Liter (km/L) 12.75 km/L
Cost per Mile (at $3.50/gal) $0.117 / mile
Values calculate live as you adjust inputs.

About Gas Mileage Calculator

The Gas Mileage Calculator calculates real-world automobile fuel efficiency by dividing miles traveled by the volume of gasoline or diesel consumed between fill-ups.

What is Gas Mileage Calculator?

The Gas Mileage Calculator calculates real-world automobile fuel efficiency by dividing miles traveled by the volume of gasoline or diesel consumed between fill-ups.

How to Use This Calculator

  1. Fill your gas tank and record current odometer reading.
  2. On next fill-up, record trip miles and gallons pumped.
  3. Enter both numbers to see your exact MPG and fuel cost per mile.

The Mathematical Formula & Variables

MPG = Miles / Gallons; L/100km = 235.215 / MPG; Cost per Mile = Price per Gallon / MPG

Step-by-Step Worked Example

Scenario: Drove 360 miles and pumped 12.0 gallons at $3.50/gallon.

  1. MPG = 360 / 12 = 30.0 MPG.
  2. Metric conversion: 235.215 / 30 = 7.84 L/100km.
  3. Cost per mile: $3.50 / 30 = $0.117 per mile.

Result: 30.00 MPG (7.84 L/100km)

Frequently Asked Questions

Why is real-world MPG often lower than EPA ratings?

Aggressive acceleration, high speeds over 65 mph, heavy cargo, cold weather, and underinflated tires reduce fuel economy by 10-25%.