Skip to calculator

Fuel Cost Calculator

Trip cost, weekly/monthly/yearly totals, fuel used, and CO₂ estimate — with full unit conversions, round‑trip toggle, and per‑person split. Works offline.

Trip Inputs

Ready
Cost per trip
—
Fuel per trip
—

Details & Totals

ItemValueNotes
Please enter distance, efficiency, and fuel price.

Automated Tests

Quick checks for unit conversions and totals.

Fuel Cost Calculator: Trip, Commute & Road Trip Budgeting — Units, Conversions & CO₂

Table of Contents
  1. What this calculator does
  2. Efficiency units explained (km/l, l/100km, mpg)
  3. Distance, round‑trip math & extras
  4. Weekly, monthly & yearly planning
  5. Tips to improve real‑world mileage
  6. CO₂ estimates & why they matter
  7. How to use this page
  8. FAQs

1) What this calculator does

Enter your route distance, vehicle efficiency, and fuel price to get an instant estimate of fuel used, cost per trip, and projected costs per week, month, and year. You can include tolls and parking, split the cost across passengers, and switch between units like km/l, l/100km, and mpg. The output also shows an approximate CO₂ footprint based on liters burned.

2) Efficiency units explained (km/l, l/100km, mpg)

km/l means how many kilometers you can travel using one liter of fuel — higher is better. l/100km flips the fraction: how many liters you burn to drive 100 km — lower is better. mpg is miles per gallon; this tool uses US gallons (3.785 L). Internally the math converts any unit to liters per km, so totals are apples‑to‑apples.

3) Distance, round‑trip math & extras

Distance is entered as one‑way and doubled for round trips. Tolls and parking are added per trip. If multiple people share the ride, use “People splitting cost” to get a per‑person number.

4) Weekly, monthly & yearly planning

Enter how many trips you make per week (e.g., 10 for a 5‑day commute with round trips). The calculator rolls this up into weekly, monthly (~4.33 weeks), and yearly (52 weeks) totals, so you can budget ahead or compare vehicles.

5) Tips to improve real‑world mileage

6) CO₂ estimates & why they matter

Burning fuel releases CO₂ as a function of carbon content. For approximate planning, gasoline is ~2.31 kg CO₂ per liter and diesel ~2.68 kg per liter. These are tailpipe emissions and don’t include upstream refining/transport.

7) How to use this page

  1. Pick your units and currency.
  2. Enter distance (one‑way), trip type, efficiency, and fuel price.
  3. Add tolls/parking and the number of people sharing, if any.
  4. Set trips per week for commute projections.
  5. Click Calculate, then export CSV or print a summary.

8) FAQs

Does driving style change results?
Yes. Aggressive driving, heavy traffic, and frequent short trips can reduce efficiency significantly. Treat these results as estimates.
Can I enter price per gallon?
Yes — select mpg as your efficiency unit and the price input switches to “per gallon.”
Is the CO₂ value precise?
No. It’s an approximation for educational use, based on typical emission factors.