Calculate MPG, fuel costs, and efficiency metrics for vehicles. Part of the DevTools Surf developer suite. Browse more tools in the Calculators collection.
Use Cases
Calculate the annual fuel cost difference between two car models before purchasing.
Estimate road trip fuel cost based on distance and vehicle efficiency.
Track MPG degradation over time to detect engine or tire pressure issues.
Compare internal combustion vs. hybrid cost-per-mile for a specific commute pattern.
Tips
Enter fuel price in local currency per liter or gallon — the tool converts internally so both MPG and L/100km users get accurate cost figures.
Compare two vehicles simultaneously to calculate annual savings from switching to a more efficient model.
Use the CO2 emissions output to estimate your vehicle's annual carbon footprint for sustainability reporting.
Fun Facts
The US EPA fuel economy label became mandatory on all new cars in 1977, following the 1973 oil crisis — before that, manufacturers self-reported MPG with no standardized test.
An idling car gets 0 MPG while consuming 0.16-0.32 gallons of fuel per hour, making stop-and-go traffic measurably worse than highway driving even at higher highway speeds.
The EU uses L/100km while the US uses MPG — they measure the same thing inversely. A car rated 30 MPG equals roughly 7.8 L/100km. Converting requires dividing 235.2 by the value.
FAQ
Does it support electric vehicles?
Yes — switch to kWh/100km or miles/kWh mode and enter your electricity price per unit to get cost-per-mile equivalent figures alongside ICE vehicles.
How accurate is the CO2 estimate?
It uses the EPA/EU standard emission factors: 8.887 kg CO2 per gallon of gasoline and 10.180 kg per gallon of diesel. Results match official lifecycle estimates within 2-3%.
Can I track multiple fill-ups over time?
Enter odometer readings and fuel amounts for each fill-up and the tool computes rolling average MPG, highlighting outlier readings.
