Fuel Consumption Calculator ⛽
Instantly compute your vehicle’s fuel consumption in L/100km, km/L, and MPG. Enter the distance you traveled and the fuel you used. Optionally add your fuel price and a planned trip distance to estimate cost per km/mile and total trip cost. Everything runs locally in your browser — no tracking, no sign‑in.
Calculator
About This Fuel Consumption Calculator
This Fuel Consumption Calculator is a fast, privacy‑friendly way to understand how efficiently your vehicle uses fuel, no matter where you drive. It supports the three most common formats used around the world: L/100km (liters per 100 kilometers), km/L (kilometers per liter), and MPG (miles per gallon). Enter two numbers — how far you drove and how much fuel you used — and the tool instantly shows the full picture, including optional cost per kilometer or mile and a quick trip cost estimator. There is nothing to install, no registration, and no tracking. Everything runs locally in your browser so you can use it confidently at the pump, in the garage, or while planning a road trip.
Understanding fuel consumption is useful for far more than curiosity. It helps drivers compare cars honestly, budget for commutes, and detect mechanical issues early. If your regular route suddenly requires more fuel, you might have a tire pressure problem, a clogged air filter, or an alignment issue. For families and fleets, recording consumption over time can highlight the real‑world impact of driving style, cargo weight, and even seasonal weather. Because this tool reports in multiple units, you can also make sense of car reviews and manuals from other regions that use different measurement systems.
What Is Fuel Consumption?
Fuel consumption describes how much fuel a vehicle needs to travel a certain distance. In many countries, efficiency is expressed as liters per 100 kilometers (L/100km): lower is better because it means fewer liters are required. Some places prefer kilometers per liter (km/L), where higher values are better. In the United States and a few other regions, efficiency is usually shown as miles per gallon (MPG). All three measure the same thing and can be converted mathematically. A useful rule of thumb is that if your L/100km figure goes down, your MPG goes up, and vice versa.
How the Calculator Works
- L/100km is computed as
(liters ÷ kilometers) × 100. - km/L is
kilometers ÷ liters. - MPG is
miles ÷ gallons(US gallons). The tool converts between kilometers and miles, and liters and gallons automatically. - When you enter a fuel price, the calculator estimates cost per kilometer and cost per mile, in your selected currency units.
- Provide a planned trip distance to see fuel needed and total trip cost based on the consumption derived from your last fill‑up.
Step‑by‑Step: How to Use It
- Reset your trip odometer when you refuel, or note your starting mileage.
- Drive normally until the next fill‑up or measurement point.
- Enter the distance driven and pick kilometers or miles.
- Enter the fuel used and pick liters or gallons (US).
- (Optional) Add your local fuel price per liter/gallon.
- (Optional) Enter a planned trip distance to budget in advance.
- Press Calculate to view L/100km, km/L, MPG, and cost estimates instantly.
Where & When to Use
- At the pump: After filling up, record odometer and liters/gallons to track real‑world consumption.
- Trip planning: Estimate how much fuel you will need and how much it will cost for vacations or work travel.
- Vehicle comparisons: Test different cars, routes, tire types, or driving styles and see the impact in minutes.
- Maintenance checks: Spot issues early by noticing trends — rising L/100km can hint at low tire pressure or overdue filters.
- Budgeting: Convert between units so that international car reviews and manuals make sense for your region.
Examples
Suppose you drove 425 kilometers and used 28.7 liters of fuel. Your consumption is (28.7 ÷ 425) × 100 = 6.75 L/100km. The same trip equals 425 ÷ 28.7 = 14.8 km/L. Converting to imperial units yields ~34.8 MPG. If your local fuel price is 1.75 per liter, your cost per kilometer is the price per liter divided by km/L, which is about 0.118 per km. If you are planning a 320‑kilometer journey with the same efficiency, you can expect to use roughly 21.6 liters and spend about 37.8 in fuel.
Tips to Reduce Fuel Use
- Keep tires inflated to the recommended pressure and remove unnecessary cargo weight.
- Accelerate smoothly, anticipate traffic lights, and maintain steady speeds where safe.
- Avoid long warm‑ups and idling; combine short errands into one loop when possible.
- Follow your vehicle’s maintenance schedule for filters, spark plugs, and oil changes.
- Use roof racks and cargo boxes only when needed — they increase aerodynamic drag.
FAQ
Q: Does this calculator work for both metric and imperial units?
A: Yes. Choose kilometers or miles and liters or gallons; the results are shown in all three formats so you can compare easily.
Q: Are US and Imperial gallons the same?
A: No. This tool uses US gallons (3.785 L). If your figure comes from Imperial gallons (4.546 L), convert liters first for accurate MPG.
Q: Can I save my entries?
A: For privacy, the basic version does not save data. You can export results or record them in your notes or spreadsheet.
Q: Is any of my data uploaded?
A: No. All calculations happen in your browser. There are no cookies or analytics scripts.
Glossary
- L/100km: Liters of fuel needed to drive 100 kilometers. Lower numbers indicate better efficiency.
- km/L: Kilometers traveled per liter of fuel. Higher numbers indicate better efficiency.
- MPG: Miles traveled per US gallon of fuel. Higher numbers indicate better efficiency.