Fuel Consumption Calculator

About the Fuel Consumption Calculator

Fuel consumption is measured differently around the world — miles per gallon (MPG) in the US, liters per 100 kilometers (L/100km) in Europe and most of the world, and kilometers per liter (km/L) in parts of Asia and South America. This calculator converts between all three formats and computes fuel costs for any distance.

Whether you're comparing a rental car's spec sheet in Europe to your car back home, planning a road trip budget, or evaluating which vehicle offers the best economy, this calculator handles the math. Enter your distance traveled, fuel used, and fuel price to get consumption in every standard unit plus cost per mile and cost per kilometer.

The comparison table lets you enter up to five vehicles side by side, showing which one is cheapest for your specific commute distance. Combined with real-time fuel prices, you can make truly informed decisions about vehicle purchases, rentals, or route planning.

When This Page Helps

Stop guessing at gas mileage. This calculator gives you fuel economy in the standards used around the world, plus the cost per mile and per kilometer that matter for planning.

It is useful because MPG, L/100km, and km/L can be translated back and forth quickly, making vehicle comparisons and trip budgeting much easier. That gives you a cleaner way to compare a car, truck, or rental before you spend money.

How to Use the Inputs

1. Enter the distance traveled in miles or kilometers.
2. Enter the fuel used in gallons or liters.
3. The calculator shows MPG, L/100km, and km/L.
4. Enter a fuel price to see cost per mile and cost per kilometer.
5. Use the comparison section to pit two vehicles head-to-head.
6. Adjust the annual distance to see projected yearly fuel costs.
7. Try the presets for common vehicle types.

Example Calculation

Tips & Best Practices

• Track MPG over several fill-ups for a reliable average — one tank can be misleading.
• Tire pressure, cruise control, and steady acceleration are the three easiest ways to improve MPG.
• Fuel economy drops significantly above 55 mph due to aerodynamic drag.
• Winter fuel economy is typically 10–20% worse than summer due to denser air and cold tires.
• Remove unnecessary weight and roof racks when not in use to boost economy.
• Use the trip computer in your car to cross-check calculator results.

Global Fuel Economy Standards

Different countries report fuel consumption differently, which makes cross-border car comparisons confusing. The US uses MPG (miles per gallon), Europe mandates L/100km, Japan uses km/L, and the UK uses Imperial MPG (which is about 20% higher than US MPG because an Imperial gallon is larger).

How Driving Habits Affect Consumption

Aggressive acceleration can increase fuel consumption by 15–30%. Speeding above 55 mph costs roughly 1% per additional mph. Idling consumes 0.2–0.5 gallons per hour for no distance. Combining errands into one trip avoids cold-start fuel penalties.

Fuel Economy Across Vehicle Types

Subcompact cars average 30–38 MPG, midsize sedans 25–32 MPG, crossover SUVs 22–28 MPG, full-size trucks 16–22 MPG, and hybrids 42–58 MPG. Plug-in hybrids can exceed 100 MPGe for short trips. Knowing your vehicle's real-world economy is the first step to controlling fuel expenses.

Frequently Asked Questions

• What is the difference between MPG and L/100km?

  MPG measures distance per unit fuel (higher is better). L/100km measures fuel per distance (lower is better). They are inversely related.

• How do I convert MPG to L/100km?

  L/100km = 235.215 ÷ MPG. For example, 30 MPG = 235.215 ÷ 30 = 7.84 L/100km.

• What counts as good fuel economy?

  In the US, 25–30 MPG is average for a sedan. 30–40 MPG is good. Hybrids hit 45–60 MPG, and EVs equivalent can exceed 100 MPGe.

• Why does my actual MPG differ from EPA ratings?

  EPA tests use standardized cycles. Real-world driving varies with traffic, speed, weather, tire pressure, AC use, and driving style.

• Does highway or city driving give better MPG?

  For traditional engines, highway usually gives better MPG due to steady speeds. Hybrids often do better in city driving where regenerative braking recaptures energy.

• How do I calculate fuel economy from a tank fill-up?

  Fill completely, reset the trip odometer, drive normally, fill again, and divide miles driven by gallons pumped. Using the same pump and filling to the same level each time makes the result more consistent.