Fuel Consumption Calculator Know Your Real Cost Before You Drive
Most drivers fill up, watch the number climb on the pump, and drive off without ever working out what that tank actually cost per mile, and by the time the next bill arrives, there’s no way to tell where the money went. A proper fuel consumption calculator fixes that gap, turning your distance, fuel economy, and local fuel price into a real number instead of a rough guess. Whether your car’s manual reads in MPG, L/100km, or km/L, and whatever currency you’re pricing fuel in, this tool reads your numbers as you already know them and hands back an answer in the same terms.
Quick Answer: Fuel cost equals distance divided by fuel economy, multiplied by fuel price, so 300 miles at 28 MPG and $4.07 a gallon works out to $43.61 and roughly 10.71 gallons burned. Enter your own numbers into the calculator below for your exact figure, in your own unit and currency.
Calculator
Supported Units: MPG (US gallon), MPG (UK Imperial gallon), L/100km, km/L.
Supported Currencies: USD, CAD, AUD, GBP, EUR.
Your Results: Fuel Used, Fuel Cost, Cost Per Mile, Monthly Cost, Annual Cost.
Why Use This Fuel Consumption Calculator
Instant calculation. Your result appears the moment you hit calculate, with no page reload and no waiting.
Accurate formulas. Every calculation runs on the same fuel consumption math used by EPA and RAC fuel guidance, not a rough estimate.
Multiple units in one tool. MPG, L/100km, and km/L all work side by side, so you never need to convert anything by hand first.
Multiple currencies. USD, GBP, EUR, AUD, and CAD are all built in, so your local fuel price plugs in directly.
Compare vehicles. Run two vehicles through the same trip and see exactly which one costs less and by how much.
Trip and monthly planning. The same calculator handles a single trip, a full road trip, or your regular monthly commute.
No signup, no app, no data stored. You get your number and nothing else is asked of you.
How To Calculate Fuel Consumption
Step 1. Enter your distance in miles or kilometres.
Step 2. Enter your vehicle’s fuel economy in MPG, L/100km, or km/L.
Step 3. Enter your local fuel price in your currency.
Step 4. Click Calculate.
Step 5. View your fuel used, total cost, and cost per mile instantly.
There is no manual arithmetic required here. The calculator converts your chosen unit behind the scenes and hands you back a plain-language breakdown, so a driver entering kilometres and a driver entering miles both get an answer they can act on. If you want to see exactly how the numbers get from your inputs to that final figure, the worked examples in the next section walk through it step by step.
What You’ll Get After Calculation
Every calculation returns a full breakdown, not just a single number.
Fuel Used, in litres or gallons depending on your chosen unit.
Trip Cost, the total fuel spend for the distance you entered.
Monthly Cost, your trip cost scaled to a full month of similar driving.
Annual Fuel Cost, the same figure projected across a full year.
Cost Per Mile, useful for comparing against a second vehicle or a different route.
Comparison Between Vehicles, if you enter a second vehicle’s fuel economy alongside your own.
Potential Savings, showing what a more efficient vehicle or driving habit would save you over a year.
Fuel Consumption Formula
Every result on this page traces back to one relationship: how much fuel a distance actually consumes, and what that fuel costs at today’s price. In metric terms, litres consumed equals your car’s L/100km rating multiplied by the distance in kilometres, then divided by 100, with the final cost equal to that litre figure multiplied by your local price per litre. Working in MPG flips the arithmetic slightly, since gallons consumed equals distance divided by MPG, but the logic underneath stays identical.
MPG Formula
Take a car rated at 32 MPG covering 210 miles. Divide 210 by 32, and you get 6.56 gallons burned, which at $3.95 a gallon comes to $25.91 for the drive, or about $0.123 per mile.
L/100km Formula
Take a car rated at 8.5 L/100km over 500 km. Multiplying 8.5 by 500 and dividing by 100 gives 42.5 litres used, and at $1.75 a litre that comes to $74.38 total, or roughly $0.149 per kilometre.
km/L Formula
Drivers across most of Asia think in km per litre rather than litres per 100km. At 12 km/L over 400 km, dividing 400 by 12 gives 33.33 litres burned for the journey, and our km/L calculator runs this exact formula directly if it’s the unit you use daily.
Real World Examples
Numbers mean more once they are attached to a situation you actually recognize, whether that’s your daily commute or a family trip you’re already planning. The five scenarios below use realistic mileage, fuel economy, and pricing so you can see exactly how the formula plays out before you run your own numbers through the calculator above.
Trip Example
A 45 mile round-trip commute at 30 MPG and $4.07 a gallon costs $6.11 in fuel each day, or roughly $134 across a 22 working day month.
Monthly Example
At 1,250 monthly miles and 28 MPG, monthly fuel cost lands at $181.70, and that scales to $2,180.40 across a full year at a steady price.
Road Trip Example
A 900 mile road trip at 26 MPG and $4.07 a gallon burns 34.6 gallons and costs $140.83 in fuel alone, before tolls or food.
Family Vacation Example
A 1,400 mile family vacation split across two drivers in a 24 MPG SUV costs $237.42 in fuel, or $59.36 per person across a group of four.
Truck Example
A semi truck averaging 6.5 MPG on diesel over an 800 mile haul burns 123 gallons, costing $516.60 at $4.20 a gallon for diesel. Our truck fuel calculator handles this exact scenario with load and route adjustments.
What Is Good Fuel Consumption
A fuel consumption rate below 7.0 L/100km, above 33 MPG in US terms, counts as good for a standard petrol car in 2026. Below 6.0 L/100km, above 39 MPG, is excellent.
Petrol: 6.5 to 8.5 L/100km (28 to 36 MPG) is typical for a mid-size sedan. Diesel: 5.0 to 7.0 L/100km (34 to 47 MPG), usually 0.5 to 1.5 L/100km lower than the petrol equivalent.
Hybrid: 4.0 to 5.5 L/100km (43 to 59 MPG) for a standard hybrid sedan. SUV: 7.5 to 10.0 L/100km (23 to 31 MPG) for a compact SUV.
Truck: 11.0 to 17.0 L/100km (14 to 21 MPG) for a full-size pickup or truck.
Motorcycle: 3.0 to 4.5 L/100km (52 to 78 MPG), varying sharply by engine size.
Electric (MPGe equivalent): 2.5 to 3.5 L/100km (67 to 94 MPGe), the most efficient category by a wide margin.
Factors That Affect Fuel Consumption
Terrain, air conditioning, traffic, fuel quality, engine size, weather, vehicle load, and driving style all move your real fuel consumption away from the number on the window sticker.
Terrain: Hills and mountain routes can raise fuel consumption by 10 to 20 percent compared to flat driving.
Air conditioning: Running AC in city driving increases fuel use by 5 to 10 percent, and by up to 20 percent in stop-start traffic.
Traffic: Stop-start city traffic burns 20 to 30 percent more fuel per mile than steady motorway cruising.
Fuel quality: Using a lower octane than your engine requires can reduce efficiency by 5 to 10 percent over time.
Engine size: Larger engines burn more fuel at idle and under light load, even when top-end power is rarely used.
Weather: Cold temperatures below 20°F (minus 7°C) reduce fuel economy by 15 to 24 percent.
Vehicle load: Every extra 100 pounds (45 kg) reduces fuel economy by 1 to 2 percent, and a roof box adds a 25 to 40 percent drag penalty at motorway speed.
Driving style: Aggressive acceleration and braking can cut fuel economy by 15 to 30 percent compared to smooth, anticipatory driving.
Ways To Reduce Fuel Consumption
Maintain tyre pressure. Potential saving: 3 percent. Drive smoothly; avoid hard acceleration. Potential saving: 20 percent. Reduce motorway speed from 70 to 60 mph. Potential saving: 15 percent. Combine short cold-start errands into one trip. Potential saving: 10 percent. Remove unused roof racks or boxes. Potential saving: up to 20 percent at motorway speed. Keep up with engine maintenance and air filters. Potential saving: up to 10 percent. Reduce unnecessary vehicle weight and cargo. Potential savings: 1 to 2 percent per 100 lbs removed.
Fuel Consumption Benchmarks
| Region | Average MPG | Average L/100km |
| USA | 26.4 MPG | 8.91 L/100km |
| Canada | 26.4 MPG | 8.9 L/100km |
| UK | 45.6 MPG | 6.2 L/100km |
| Australia | 24.7 MPG | 9.5 L/100km |
| Europe (EU average) | 42.8 MPG | 5.5 L/100km |
These figures reflect new vehicle fleet averages as of 2025, based on EPA Automotive Trends data and RAC Fuel Watch reporting.
Compare Your Vehicle
Enter your MPG or L/100km above and see instantly where your vehicle sits against its class average.
Above Average: Under 6.5 L/100km (over 36 MPG), better than most vehicles in its class. Average: 6.5 to 9.0 L/100km (26 to 36 MPG), in line with typical fleet performance. Below Average: 9.0 to 12.0 L/100km (20 to 26 MPG), worth checking maintenance and driving habits. Poor: Over 12.0 L/100km (under 20 MPG), significantly higher than the class average and worth investigating.
Fuel Cost By Vehicle Type
Sedan: $154 to $196 per month at 1,250 miles, depending on engine size.
SUV: $196 to $237 per month for compact to mid-size SUVs. Pickup: $231 to $299 per month for full-size trucks.
Truck (commercial): Cost scales by route and load; see our truck fuel calculator for a diesel-specific breakdown.
Hybrid: $95 to $135 per month, roughly 30 to 40 percent lower than an equivalent petrol sedan.
Motorcycle: $45 to $75 per month for most standard commuter bikes.
RV: $400 to $700 per month depending on class and mileage, given typical fuel economy of 6 to 10 MPG.
Boat: Cost runs per hour rather than per mile; use our boat fuel calculator for an engine-specific estimate.
Fuel Budget Planning
Weekly Budget: Multiply your typical weekly mileage by your cost per mile to get a quick weekly estimate.
Monthly Budget: Use the Monthly Cost tab above, along with your average monthly mileage, to get a reliable number to plan around. Annual Budget: Multiply your monthly figure by 12, then add 15 to 20 percent for winter months where fuel economy typically drops.
Family Budget: Add up each household vehicle’s monthly cost separately, since fuel economy and mileage usually differ per car. Business Budget: Track cost per mile per vehicle and multiply by expected monthly mileage for expense forecasting.
Fleet Budget: Use our fleet fuel calculator to calculate weighted average cost across multiple vehicles at once.
Common Fuel Calculation Mistakes
Using the wrong MPG figure. Manufacturer ratings run 10 to 20 percent higher than real-world driving, so real-world estimates give a more honest number.
Using an outdated fuel price. Fuel prices shift weekly, so check a current local price rather than relying on memory.
Confusing Imperial and US MPG. The UK gallon is 4.546 litres while the US gallon is 3.785 litres, so a 40 UK MPG car is only about 33.3 US MPG.
Ignoring idling time. Idling burns fuel with zero distance covered, which standard trip calculations miss entirely.
Ignoring towing weight. Towing a trailer or caravan can drop MPG by 20 to 40 percent depending on trailer weight and shape.
Ignoring air conditioning load. AC use adds 5 to 20 percent to fuel consumption depending on traffic conditions, and is often left out of simple estimates.
Common Fuel Calculation Mistakes
Most Popular MPG Calculator, measures your exact real-world MPG from two fill-ups. Monthly Fuel Cost Calculator, turns your commute into a monthly and annual budget. Cost Per Mile Calculator, adds insurance, maintenance, and depreciation to fuel cost.
Commercial Truck Fuel Calculator, diesel cost per mile and per trip for trucks. Fleet Fuel Calculator, total spend and weighted MPG across a fleet.
Conversions Fuel Unit Converter, switches between MPG, L/100km, and km/L instantly. km/L Calculator, dedicated km per litre calculation.
EV EV vs Petrol Calculator, compares running costs over a full ownership period.
Trip Planning Trip Fuel Calculator, full route cost with passenger splitting. Towing Fuel Calculator, MPG drop and cost by trailer weight.
Fleet Fleet Fuel Calculator, see Commercial section above.
Agriculture Tractor Fuel Calculator, diesel cost per hour, acre, and season.
Marine Boat Fuel Calculator, marine fuel cost per hour and per nautical mile.
Recently Added Idle Fuel Calculator, shows exactly what idling costs per hour, day, and year. Generator Fuel Calculator, running cost by wattage and load for generators.
Frequently Asked Questions
Methodology
Calculation Method: Every result runs on the standard distance-over-efficiency relationship, converted automatically between metric and imperial units so the same trip produces a consistent answer regardless of which format you entered it in.
Data Sources: EPA fueleconomy.gov 2026 dataset, EPA Automotive Trends Report 2025, RAC Fuel Watch, Consumer Reports, and AAA Your Driving Costs 2025.
Editorial Process: Every figure on this page is checked against at least one government or industry source before publishing.
Review Process: The FuelConsumptionCalc Editorial Team reviews pricing and benchmark data on a monthly cycle.
Update Frequency: Fuel prices and fleet averages are reviewed monthly, with major formula or benchmark changes reviewed annually.
Last Updated: July 2026.
Sources
EPA (fueleconomy.gov and Automotive Trends Report), US Department of Energy, AAA (Your Driving Costs), RAC Fuel Watch, Consumer Reports.
About FuelConsumptionCalc
FuelConsumptionCalc was built to answer one simple question every driver eventually asks: what does this actually cost me. Every figure here is checked against EPA, RAC, and Consumer Reports data rather than rounded off a guess, so the number you land on is one you can genuinely plan a budget around.
All benchmark figures and fuel prices are reviewed monthly against EPA, RAC, Consumer Reports, and AAA data, with the review date shown in the Methodology section above. No account, signup, or personal data is required to use any calculator on this site.
Last Updated: July 2026.