⛽ Fuel Cost Calculator

Estimate trip, monthly, and annual fuel spend from distance, fuel economy (MPG or L/100km), and pump price. Supports metric and imperial units with vehicle comparison.

Trip Fuel Cost From Distance, MPG, and Pump Price

BrainyCalculators editorial insight — unique to this tool

300 miles at 25 mpg with $3.80/gal = $45.60 fuel — US road trips. India: 400 km at 15 km/L with ₹102/L ≈ ₹2,720. EV comparison needs kWh/100 km and electricity rate, not this petrol/diesel model.

When to use this calculator

Use for ICE vehicle trip fuel budgeting. For EV charging cost, use EV Charging Cost (if available).

Reference	Value	Context
US average MPG	~25 combined	New vehicles
India compact car	15–18 km/L	City/highway mix
US gas (2024)	$3.50–4.00/gal	Varies by state
India petrol	₹95–110/L	Metro 2024 range

Need to measure efficiency from a fill-up first?

This page estimates fuel spend from distance and known efficiency. To calculate L/100km or MPG from litres used and distance driven, use the Fuel Consumption Calculator →

Distance (km)

Fuel Efficiency (L/100km)

Fuel Price ($/L)

Trips per Week optional

What is Fuel Cost?

Fuel cost is the dollar amount to drive a given distance: Fuel Cost = (Distance ÷ MPG) × Price per Gallon, or in metric: (Distance × L/100km ÷ 100) × Price per Litre. This page answers the budgeting question — how much will this trip, commute, or year of driving cost at today’s pump price?

Use it for road-trip planning, commute budgeting, fleet cost estimates, and side-by-side comparison of two vehicles’ annual fuel spend. Enter distance, known efficiency, and local fuel price to get trip, monthly, and yearly totals.

If you need to measure your vehicle’s actual efficiency from a fill-up (litres used ÷ km driven) or convert between L/100km and MPG, use the Fuel Consumption Calculator. For calculating MPG from miles and gallons with vehicle comparison tabs, use the Fuel Economy Calculator.

Fuel Cost Formulas

Metric

Fuel (L) = Distance (km) × Efficiency (L/100km) ÷ 100

Cost = Fuel (L) × Price ($/L)

Imperial

Fuel (gal) = Distance (mi) ÷ Efficiency (MPG)

Cost = Fuel (gal) × Price ($/gal)

Monthly estimate assumes 4.33 weeks per month.

How to Calculate Fuel Cost

1

Choose Metric or Imperial

Select the unit system you use — kilometres and litres, or miles and gallons.
2

Enter Trip Distance

Enter the total one-way or round-trip distance in km or miles.
3

Enter Fuel Efficiency

Enter your vehicle's fuel consumption in L/100km or miles per gallon (MPG).
4

Enter Fuel Price

Enter the current fuel price per litre or per gallon at the pump.
5

Optionally Add Weekly Trips

Enter how many times per week you make this trip to see a monthly fuel cost estimate.

Real-World Example

A 500 km road trip in a car that uses 8 L/100km, with fuel at $1.50/L.

Fuel needed = 500 × 8 ÷ 100 = 40 litres

Total cost = 40 × $1.50 = $60.00

Cost per km = $60 ÷ 500 = $0.12/km

How the Fuel Cost Calculator Works

Formula, assumptions, and calculation steps for this daily life tool.

Methodology

Daily-life calculators turn common date, time, budget, and household inputs into quick practical estimates.

Calculation Steps

Enter the everyday values requested by the form.
Normalize dates, times, currency, or quantities as needed.
Apply the simple arithmetic or calendar rule.
Show the result in a format that is easy to act on.

Assumptions and Limits

Local rules, time zones, and rounding choices may affect real-world results.
The calculator uses the values entered and does not verify external schedules.
Use results as a planning aid.

Frequently Asked Questions

How do I find my car's fuel efficiency?

Fill your tank, reset the trip odometer, drive normally, then fill up again. Divide the litres added by the kilometres driven and multiply by 100 to get L/100km. Or divide kilometres by litres for km/L.

How do I convert MPG to L/100km?

Use the formula: L/100km = 235.21 ÷ MPG. For example, 30 MPG = 235.21 ÷ 30 = 7.84 L/100km.

Does speed affect fuel consumption?

Yes significantly. Most cars are most efficient between 80–100 km/h. Driving at 120 km/h can use 20–30% more fuel than 90 km/h due to increased aerodynamic drag.

How much does idling cost?

A typical car burns 0.5–1 litre per hour while idling. At $1.50/L that's $0.75–$1.50 per hour. Turning off your engine if stopped for more than 60 seconds saves fuel.

How can I reduce my fuel costs?

Keep tyres properly inflated, remove excess weight, avoid rapid acceleration and braking, combine errands into one trip, and maintain your vehicle regularly. A well-maintained car can use up to 15% less fuel.

Real-World Applications

🗺️

Road Trip Budget

Estimate total fuel cost for a cross-country trip before departure and plan refuelling stops based on tank range and pump prices.

🚗

Commute Cost Analysis

Calculate the true daily, monthly, and annual cost of a long commute — often surprising compared to a closer home or remote work option.

🚕

Rideshare & Delivery Profitability

Gig workers calculate fuel cost per mile to ensure their per-trip earnings exceed the true variable cost of driving.

🔄

EV vs Petrol Comparison

Compare annual fuel cost for a 28 MPG petrol car vs the electricity cost of an equivalent EV at current rates.

🚌

Fleet Fuel Budgeting

Estimate monthly fleet fuel spend across a company vehicle fleet based on each vehicle's mileage and consumption rate.

✈️

Driving vs Flying Cost

Calculate the fuel cost of driving vs airfare to compare total travel costs including parking and flexibility factors.

Common Mistakes

Using the EPA combined rating as actual consumption

Real-world fuel economy runs 10–20% below EPA ratings for most drivers — use a correction factor or your own measured consumption for accurate cost estimates.

Not factoring in fuel price variability

Fuel prices can vary by $1.00/gallon over a year and by region. For annual cost projections, use a range of price scenarios rather than today's price.

Confusing one-way vs round-trip distance

For commute calculations, multiply the one-way distance by 2 for the daily round trip — then by working days per year for the annual total.

Only counting fuel cost, not total vehicle cost

Fuel is typically 25–35% of total vehicle ownership cost — insurance, depreciation, maintenance, and tyres are the other major components often overlooked.

Using US gallons when calculating for non-US vehicles

A UK or Australian vehicle's fuel consumption is measured in litres or Imperial MPG — converting directly to US gallons produces incorrect results.

Annual Fuel Cost by MPG (15,000 mi/yr at $3.80/gal)

MPG	Gallons / Year	Annual Cost	vs 30 MPG
15 MPG	1,000 gal	$3,800	+$1,900/yr
20 MPG	750 gal	$2,850	+$950/yr
25 MPG	600 gal	$2,280	+$380/yr
30 MPG	500 gal	$1,900	Baseline
40 MPG	375 gal	$1,425	−$475/yr
50 MPG	300 gal	$1,140	−$760/yr

References

U.S. Department of Energy. Fuel Economy Guide. fueleconomy.gov, 2024.
U.S. Energy Information Administration. Weekly Retail Gasoline and Diesel Prices. EIA, 2024.
AAA. Your Driving Costs — How Much Are You Really Paying to Drive? AAA, 2023.
Bureau of Transportation Statistics. National Household Travel Survey. BTS, 2023.
Consumer Reports. Real-World MPG vs EPA Ratings. Consumer Reports, 2024.