About Fuel Cost Calculator
Estimate fuel cost for any trip. Supports L/100km, MPG, km/L, Canadian and US units. Free, no sign-up required.
How to use
- Enter your trip distance and choose km or mi from the unit dropdown. For round trips, enter the total distance there and back — the calculator does not double the number for you.
- Enter your vehicle's fuel efficiency and pick its unit: L/100km (Canadian standard), MPG (US), MPG-UK (Imperial), or km/L. If your dash shows a different unit than your fuel price, the tool converts internally.
- Type the fuel price and pick its unit ($/L for Canada, $/gal for the US). Use the price you actually paid at the pump, including taxes — gas pump prices in Canada always include all federal and provincial fuel taxes.
- Read the Total Cost output. The tool also shows total fuel volume consumed so you can sanity-check against your tank size on a long trip.
- For business-use trips, multiply your total cost by the percentage of the trip that was business (not commuting). Or use the Canadian per-km flat rate of 72¢/km for the first 5,000 km and 66¢/km thereafter (CRA 2025) instead of actual costs — pick whichever is higher.
- To compare an EV against gas, run the calculator with the gas car's numbers, then re-run with the EV's kWh/100km × electricity rate as the equivalent fuel cost. EVs typically cost 20-30% per km of an equivalent gas car at current Canadian rates.
Examples
Toronto to Montreal in a hybrid (540 km, 5.5 L/100km, $1.62/L)
Fuel used: (540 / 100) × 5.5 = 29.7 L. Cost: 29.7 × 1.62 = $48.11. The same trip in an SUV at 12 L/100km would cost $104.98 — the hybrid saves $56.87 one way, or $113.74 round trip. That's roughly the price of a tank of gas saved per round trip.
Converting a US MPG number to L/100km
If your car gets 28 US MPG, convert to L/100km using 235.215 ÷ MPG. So 235.215 / 28 = 8.4 L/100km. A 200 km trip at 8.4 L/100km with gas at $1.55/L = (200/100) × 8.4 × 1.55 = $26.04. Always convert before you calculate, never mix units.
Annual business-use deduction for a contractor (15,000 km)
Using the CRA 2025 simplified rate: first 5,000 km × $0.72 = $3,600, plus next 10,000 km × $0.66 = $6,600. Total deduction = $10,200. Compare to actual-cost method: 15,000 km × 8 L/100km × $1.65/L = $1,980 in fuel alone, plus prorated insurance, depreciation, repairs. Whichever is larger is what you claim.
Frequently asked questions
How do I convert between L/100km and MPG?
L/100km and MPG are inverses, not direct conversions. To convert L/100km to US MPG, divide 235.215 by the L/100km value (so 8 L/100km = 29.4 MPG). To convert US MPG to L/100km, divide 235.215 by the MPG (28 MPG = 8.4 L/100km). Imperial MPG (UK gallons) uses 282.481 instead. The reason is unit math: 235.215 = 100 km × (1 mile/1.609 km) × (1 US gal/3.785 L), simplified.
Why does my real fuel cost differ from this estimate?
Real-world consumption varies with driving style, terrain, weather, and load. Highway driving at a steady 100 km/h is the most efficient; stop-and-go city traffic can use 30-40% more fuel than your published L/100km rating. Cold weather (-20°C) increases consumption 15-20% because the engine takes longer to warm up. Roof racks or trailers can add 10-25%. Use a 10-15% buffer on long trips, especially in winter or with cargo. Track real fillups over a few months to learn your personal average.
What rate should I use for business mileage in Canada?
The CRA's 2025 reasonable per-km allowance is 72¢ for the first 5,000 business kilometres and 66¢ thereafter (in the territories, add 4¢/km). This is what an employer can reimburse you tax-free for personal-vehicle business use, and the equivalent Form T2125 self-employed deduction. Beyond 5,000 km the rate drops because the CRA assumes per-km wear-and-tear is partly fixed cost spread over distance. Track your business-vs-personal split with a logbook — the CRA can demand to see it for up to six years.
How does an EV compare to a gas car for cost per km?
At Canadian average rates (~$1.55/L gas vs ~$0.13/kWh electricity), an EV uses around 18 kWh/100km vs a gas car's 8 L/100km. Cost per 100 km: gas car = 8 × $1.55 = $12.40; EV = 18 × $0.13 = $2.34. The EV is roughly 80% cheaper per kilometre on fuel/energy alone. Add in lower maintenance (no oil changes, fewer brake replacements thanks to regen) and the gap widens. The catch: charging on the road at DC fast chargers can cost $0.40-0.60/kWh, narrowing the savings on long trips.
Should I round-trip the distance or enter one-way?
Enter the total distance you will actually drive. If you're going from Toronto to Ottawa and back, enter 900 km, not 450 km. The calculator does not assume round-trip. For commuter math (daily round-trip × number of work days), calculate one round-trip cost and multiply by your monthly work days outside the tool, since other costs scale with duration too.
Why do gas prices vary so much by province?
Federal excise tax (10¢/L) is the same everywhere, but provincial fuel taxes range from ~7¢/L in Alberta to ~24¢/L in BC's Lower Mainland (which adds a TransLink levy). HST/GST also stack on top of the fuel tax — you pay tax on tax. Add carbon pricing (where applicable) and refining/distribution differences and the gap between cheapest (Alberta) and most expensive (Vancouver/Atlantic Canada) provinces is regularly 20-30¢/L. Use the price you actually paid at the pump, not a national average.
What's a 'good' fuel efficiency rating?
For 2025 gasoline cars: 6 L/100km (39 MPG) or better is excellent for a non-hybrid; 8 L/100km (29 MPG) is typical for a midsize sedan; 10 L/100km (24 MPG) is typical for a midsize SUV. Hybrids commonly hit 4-5 L/100km. Pickups and full-size SUVs often run 12-14 L/100km. Plug-in hybrids get an MPGe rating that combines electric and gas modes — useful for advertising but not directly comparable on a road trip where you've burned through the battery.
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