Fuel Cost Calculator
Plan the fuel budget for a commute, road trip or move before you leave. Enter the total distance, your real fuel economy and the pump price in matching units, such as miles with MPG and dollars per gallon, or kilometres with km/L and a local price per litre.
How to estimate trip fuel cost
-
1
Enter the full distance
Use the one-way distance or the return distance, depending on what you want to budget.
-
2
Use matched fuel economy
MPG works with gallons. km/L works with litres. If your car lists L/100 km, convert it to km/L or use the formula below.
-
3
Add the pump price
Use price per gallon for MPG or price per litre for km/L, in the currency you actually pay.
-
4
Review the estimate
The calculator divides distance by economy, then multiplies the fuel amount by the unit price.
Formula
fuel = distance ÷ economy
trip cost = fuel × price per fuel unit
Use consistent units:
| Local convention | What to enter | Cost formula |
|---|---|---|
| Miles, MPG, $/gal | distance in miles, fuel economy in MPG, price per US gallon | cost = miles ÷ MPG × price |
| Kilometres, km/L, local currency/L | distance in km, fuel economy in km/L, price per litre | cost = km ÷ km/L × price |
| Kilometres, L/100 km, local currency/L | calculate litres directly, or convert first to km/L = 100 ÷ L/100 km |
cost = km × L/100 km ÷ 100 × price |
Worked example
A 320 mile trip in a car averaging 28 MPG (US), with petrol at $3.90 per gallon:
fuel = 320 ÷ 28 = 11.43 gal
cost = 11.43 × 3.90 = $44.58
Metric example for a 420 km trip at 6.5 L/100 km and €1.80/L:
fuel = 420 × 6.5 ÷ 100 = 27.30 L
cost = 27.30 × 1.80 = €49.14
What the estimate does not include
- Route changes and detours: real roads are often longer than the map preview.
- Traffic and idling: city congestion can add 5% to 15% to fuel use.
- Weather, load and driving style: speed, air conditioning, tyres and luggage all matter.
- Tolls, parking and wear: add these separately if you need the full trip cost.
Tip: measure your own economy
Official EPA, WLTP and manufacturer figures are useful for comparison, but your actual driving can be noticeably different. For the most reliable estimate, record distance and fuel added over two or three refills, calculate your own MPG or km/L, then use that average in the calculator.
Frequently Asked Questions
Yes, if you use a distance-per-litre figure such as km/L and a price per litre. If your dashboard or brochure shows L/100 km, convert it first with km/L = 100 ÷ L/100 km, or use the L/100 km formula in the guide.
Use your own average when possible. Lab figures are designed for comparison, while real consumption changes with speed, traffic, tyres, weather and load.
For hybrids, yes, use the real average fuel economy you observe. For pure EVs, use an electricity cost calculator with kWh per mile or kWh per 100 km and price per kWh.
It follows the distance you enter. For a return trip, enter the total return distance or double the one-way result.
No. The numbers stay in your browser and are not stored or transmitted.
Related Tools
BMI Calculator
Calculate body mass index from height and weight. Shows WHO category, healthy-weight range and limitations of BMI.
GPA Calculator
Calculate grade point average from letter grades and credit hours. Supports US 4.0 and 5.0 honors scales with the standard A/B/C/D letter table.
Inflation Calculator
Calculate the equivalent purchasing power of a dollar across any two years using historical CPI data from 1913 to today.
Scientific Calculator
Full scientific calculator with trig, log, exponents, factorial, memory, parentheses and DEG/RAD toggle. Runs in your browser.
Binomial Probability Calculator
Compute exact, cumulative and tail probabilities for a binomial distribution. Enter n trials, p success rate and k successes.
Calorie Calculator
Estimate daily calorie needs for your goal using Mifflin-St Jeor BMR and activity factors. Includes deficit and surplus targets.