Fuel Cost Calculator - Trip & Commute Fuel Costs

Work out what a trip or your monthly commute costs in fuel, with km or miles, any consumption unit, and cost per person. Free, instant, and fully browser-based.

Mode

Trip fuel cost

12.67

100.0 km total · 6.5 L fuel · 6.5 L/100km · 1.950/L

How to Calculate the Fuel Cost of a Trip

The math is simple once everything is in the same units: fuel used = distance × consumption, and cost = fuel used × price. A 100 km trip in a car that uses 6.5 L/100km burns 6.5 liters; at 1.95 per liter that trip costs 12.68. Where it gets fiddly is unit conversion, which this calculator handles for you: miles convert at 1.609344 km per mile, a US gallon is 3.785 liters, a UK gallon is 4.546 liters, and 40 MPG (US) equals roughly 5.9 L/100km while 40 MPG (UK) is about 7.1 L/100km, a difference that trips up many comparisons.

The monthly commute mode multiplies your daily distance by your working days. Someone driving 25 km each way, 21 days a month, in a 6.5 L/100km car at 1.95 per liter spends about 133 per month on commuting fuel alone (with the round trip option on). Seeing that number is often the moment carpooling starts to look attractive: split between two colleagues it drops to 66.50 each, and between three to under 45.

Real-world consumption is usually 10-20% higher than the manufacturer figure, especially for short trips with a cold engine, city stop-and-go driving, roof boxes, and winter temperatures. Driving 100 km/h instead of 120 km/h on the highway typically saves around 15-20% fuel. For a more accurate number, fill the tank, reset your trip meter, and divide liters at the next fill-up by the kilometers driven, then use that figure here.

Note that fuel is only part of the true cost of driving: depreciation, insurance, maintenance, and tires often double the per-kilometer cost. For splitting a shared ride fairly, the Split Bill Calculator on ToolForte handles uneven shares, and the Speed Converter helps when comparing km/h and mph limits abroad. Everything runs free in your browser.

How the Fuel Cost Calculator Works

  1. 01Pick single trip or monthly commute mode, and enter the distance in km or miles.
  2. 02Enter your car's consumption in L/100km, km/L, or MPG (US or UK) - the calculator converts automatically.
  3. 03Enter the fuel price per liter or per gallon and how many people share the cost.
  4. 04Read the total fuel cost, liters used, and cost per person; enable round trip or set working days for a commute.

Getting your consumption number right

Manufacturer figures are optimistic; real-world consumption is typically 10-20% higher, especially in city traffic and cold weather. For an accurate number, fill your tank completely, reset the trip meter, drive normally, and at the next full fill-up divide the liters by the kilometers driven, times 100. That real L/100km figure makes every cost estimate here trustworthy.

When to Use This Tool

Use it before a road trip to budget fuel, to split costs fairly with passengers, to compare commuting by car against a monthly transit pass, or to see what a more efficient car would save you per month. The unit converters also make it easy to compare a US car's MPG with European L/100km figures.

Common Use Cases

Tips

  • Measure your real consumption tank-to-tank; it is usually 10-20% above the brochure figure.
  • Driving 100 instead of 120 km/h on the highway saves roughly 15-20% fuel.
  • For carpools, include the driver in the people count - everyone shares the cost equally.

Frequently Asked Questions

How do I calculate the fuel cost of a trip?→
Fuel used = distance x consumption, cost = fuel used x price. A 250 km trip at 6.5 L/100km uses 16.25 liters; at 1.95 per liter that is 31.69. This calculator does the unit conversions for miles, MPG, and gallons automatically.
What is the difference between US MPG and UK MPG?→
A US gallon is 3.785 liters while a UK (imperial) gallon is 4.546 liters, about 20% more. So 40 MPG (US) equals roughly 5.9 L/100km, while 40 MPG (UK) is about 7.1 L/100km. Comparing them directly without converting overstates the efficiency of the US figure.
How do I convert L/100km to km/L or MPG?→
km/L = 100 divided by L/100km, so 6.5 L/100km is about 15.4 km/L. For US MPG, divide 235.2 by the L/100km figure: 6.5 L/100km is about 36 MPG (US). This calculator accepts any of these units directly.
How much does my daily commute cost per month?→
Enter your one-way distance, enable round trip, choose monthly commute mode, and set your working days (21 is typical for a full-time month). A 25 km one-way commute at 6.5 L/100km and 1.95 per liter costs about 133 per month - carpooling with one colleague halves it.
Is fuel the total cost of driving?→
No. Depreciation, insurance, maintenance, tires, and taxes often double or triple the per-kilometer cost. Fuel is simply the most visible variable cost. For full cost comparisons, government motoring organizations publish per-km total cost estimates for typical cars.

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