Gas Mileage Calculator
Enter distance travelled and fuel consumed to calculate fuel efficiency in MPG and L/100km. Add fuel price to see cost per mile or km.
Enter distance travelled and fuel consumed to calculate fuel efficiency in MPG and L/100km. Add fuel price to see cost per mile or km.
Formula
MPG = Distance (miles) ÷ Fuel Used (gallons) | L/100km = (Fuel Used (litres) ÷ Distance (km)) × 100 | Cost per Mile = Fuel Price ÷ MPG
Miles per gallon (MPG) shows how far your vehicle travels on one gallon of fuel. Litres per 100 kilometres (L/100km) shows fuel consumption per 100 km driven. Cost per mile divides the fuel price by MPG to show operating fuel cost. Comparing these metrics across vehicles helps identify fuel-efficient options and track fleet performance.
Worked Example
300 miles travelled · 12 gallons fuel used · $3.50 per gallon:
MPG = 300 miles ÷ 12 gallons = 25 MPG
L/100km = (12 ÷ (300 ÷ 1.609)) × 100 ÷ 3.785 = 9.4 L/100km
Cost per mile = $3.50 ÷ 25 = $0.14/mile
A vehicle averaging 25 MPG costs $0.14 per mile in fuel. Over 10,000 miles, fuel costs total $1,400. Better fuel economy reduces operating costs.
Frequently Asked Questions
Use this in your workflow
Track fuel efficiency across your fleet to identify performance trends and maintenance needs. Use the Fleet Cost Per Mile Calculator to calculate total vehicle operating costs. Calculate Mileage Reimbursement for employee travel or Fuel Costs for future trips. Browse all Free Business Calculators.
Worked example: fleet vehicle comparison
Use this to compare fuel efficiency across different vehicle types in your fleet.
| Vehicle Type | Distance | Fuel | MPG |
|---|---|---|---|
| Sedan (Efficient) | 300 miles | 12 gal | 25 MPG |
| SUV (Standard) | 300 miles | 15 gal | 20 MPG |
| Truck (Large) | 300 miles | 17 gal | 17.6 MPG |
| Hybrid (Best) | 300 miles | 8 gal | 37.5 MPG |
The sedan is 25% more efficient than the SUV. Using the sedan for 100,000 annual miles (vs. SUV) saves 2,000 gallons of fuel annually. At $3.50/gallon, that's $7,000 in savings — or $14,000 using a hybrid.