Fuel Cost Calculator
Calculate fuel cost for a trip.
How to use Fuel Cost Calculator
Enter Your Trip Distance
Click the 'Distance' input field and type the total miles or kilometers for your trip. Use the dropdown menu next to the field to select your preferred unit (miles or km). For example, enter 250 for a 250-mile journey.
Input Your Vehicle's Fuel Efficiency
Click the 'Fuel Efficiency' field and enter your car's MPG (miles per gallon) or L/100km rating. Find this in your vehicle manual or check fueleconomy.gov. Enter the number and select the corresponding unit from the dropdown—MPG or L/100km.
Set Current Fuel Price
Click the 'Fuel Price' input box and enter the current price per gallon or liter in your area. Select the currency and fuel unit ($/gallon, €/liter, etc.) from the dropdown menu. You can check current prices at GasBuddy or your local gas station.
Click Calculate Button
Press the blue 'Calculate Fuel Cost' button located below all input fields. The calculator will instantly process your data and display results in the output panel to the right.
Review Your Fuel Cost Results
View the calculated total fuel cost, gallons/liters needed, and cost per mile breakdown in the results section. Use these numbers to budget for your trip or compare costs for different vehicle options.
Related Tools
Fuel cost calculator: estimate trip and commute costs
Fuel cost calculator: estimate trip and commute costs
Planning a road trip or wondering how much your daily commute really costs? Use the free fuel cost calculator on ToolHQ to get an instant estimate based on your distance, fuel efficiency, and current gas price.
A fuel cost calculator tells you how much you will spend on gas for any trip or commute by combining three inputs: how far you are traveling, how efficiently your vehicle uses fuel, and what fuel costs per gallon or liter right now.
Most drivers underestimate what their car actually costs to run. A 20-mile daily commute feels cheap until you calculate it over a year: that is over 4,800 miles annually, and at average efficiency and gas prices, it can add up to well over $1,000 in fuel alone. ToolHQ's fuel cost calculator supports both MPG and L/100km, handles one-way and round-trip calculations, and shows your cost per mile or kilometer so you have the full picture.
Key Takeaways
- Fuel cost = (Distance / Fuel Efficiency) × Fuel Price, where efficiency is in MPG or L/100km
- A 20-mile round-trip commute at 28 MPG and $3.50/gallon costs roughly $5 per day, over $1,250 per year
- ToolHQ supports both imperial (MPG) and metric (L/100km) units in a single tool
- Driving above 50 mph reduces fuel efficiency by about 7% for every 5 mph over the limit
- No data is stored or transmitted, your calculation runs entirely in the browser
How fuel cost calculations work
The formula is straightforward. To calculate fuel cost in miles and gallons:
Fuel cost = (Distance in miles / MPG) × Price per gallon
For metric users working with liters per 100 km:
Fuel cost = (Distance in km × L/100km / 100) × Price per liter
So for a 300-mile road trip in a car that gets 30 MPG, at $3.60 per gallon, you would use 10 gallons of fuel (300 / 30) at a cost of $36.
If your car's efficiency is listed in L/100km rather than MPG, you can convert between the two using: MPG = 235.214 / L/100km. A car rated at 7.0 L/100km is roughly equivalent to 33.6 MPG.
According to the U. S. Department of Energy's fueleconomy.gov, the average new car sold in the US achieves around 28 MPG combined (city and highway). Older vehicles, SUVs, and trucks typically average 18-22 MPG; modern hybrids can hit 45-55 MPG. According to Wikipedia's fuel economy article, real-world fuel consumption regularly differs from official ratings by 10-20%, depending on driving style, load, and conditions.
When a fuel cost calculator helps
The biggest use cases are trip planning, commute budgeting, and vehicle comparisons.
Road trip planning. You want to drive from Chicago to Nashville (470 miles). Your car gets 28 MPG. Gas is averaging $3.45 per gallon. The fuel cost calculator gives you the answer in seconds: about 16.8 gallons, or roughly $58 one way, $116 round trip. You can decide whether to drive or fly based on real numbers.
Commute budgeting. Your daily commute is 18 miles each way. At 25 MPG and $3.60 per gallon, that is 1.44 gallons per round trip, or $5.18 per day. Over 250 working days per year, that is $1,295 in annual fuel costs from commuting alone. Seeing that annual number often surprises people.
Comparing vehicles. You are choosing between a 22 MPG SUV and a 38 MPG hybrid. For 15,000 miles per year at $3.50 per gallon, the SUV costs about $2,386 in fuel while the hybrid costs $1,382. The difference is over $1,000 per year, or around $5,000 over five years.
Take Danny, a plumber who drives a pickup truck for work. He was spending $420 a month on gas but could not figure out where it was all going. He plugged his 17 MPG truck, his average daily mileage (68 miles), and local gas prices into the fuel cost calculator. The result: $14.82 per day, $445 per month. The number matched almost exactly. He used that data to argue for client mileage reimbursement and ended up recovering $280 per month.
How to use the ToolHQ fuel cost calculator
Five inputs, ten seconds.
- Enter trip distance. Choose miles or kilometers depending on where you are. Enter the one-way distance or the full round-trip distance, whichever you prefer.
- Select one-way or round trip. The calculator doubles the distance for round trips automatically.
- Enter fuel efficiency. Use MPG if you are in the US, L/100km if you are in the UK, Europe, or Australia. If your efficiency is listed in km/L (common in some Asian markets), convert it to L/100km by dividing 100 by your km/L value.
- Enter fuel price. Enter the current price per gallon (US) or per liter (metric). Check your local gas station app for the most accurate current price.
- Read your results. The calculator shows total gallons or liters used, total fuel cost, and cost per mile or kilometer.
No data is stored or transmitted. All calculations run in your browser.
If you are comparing driving versus another mode of transport, pair this with the unit converter to handle unit conversions, or the currency converter if you are comparing fuel prices in different countries.
Fuel efficiency by vehicle type and tips to reduce costs
Average fuel efficiency by vehicle type
| Vehicle type | Typical MPG (US) | Typical L/100km | Annual fuel cost* |
|---|---|---|---|
| Compact sedan | 32-38 MPG | 7.4-6.2 L/100km | $1,105-$1,313 |
| Midsize sedan | 26-32 MPG | 9.0-7.4 L/100km | $1,313-$1,615 |
| Midsize SUV | 22-28 MPG | 10.7-8.4 L/100km | $1,500-$1,909 |
| Pickup truck | 16-22 MPG | 14.7-10.7 L/100km | $1,909-$2,625 |
| Hybrid sedan | 42-55 MPG | 5.6-4.3 L/100km | $764-$1,000 |
| Electric vehicle | Equivalent 100+ MPGe | N/A | $500-$700 in electricity |
*Based on 12,000 miles per year at $3.50/gallon.
Tips to meaningfully reduce fuel costs
Slow down on highways. Every 5 mph above 50 mph reduces your fuel efficiency by roughly 7%. On a long highway trip, slowing from 75 to 65 mph can reduce fuel use by 14%.
Accelerate and brake smoothly. Aggressive acceleration and hard braking can cut your MPG by 15-30%. Coasting to stops rather than braking at the last second saves fuel and brakes.
Keep tires properly inflated. Under-inflated tires increase rolling resistance. Each PSI drop below the recommended level costs about 0.2% in fuel efficiency. Check your tire pressure monthly.
Remove roof racks when not in use. Roof racks create aerodynamic drag that reduces efficiency by 5-15% at highway speeds, even when empty.
Plan combined trips. Cold engine starts consume the most fuel. Combining multiple errands into one trip can save 15-20% compared to separate trips.
Priya drove a 7-year-old sedan rated at 30 MPG. After inflating her tires from 28 PSI to the recommended 35 PSI, she noticed her calculated fuel cost dropped by about $4 per week. That is just over $200 per year recovered from a 5-minute tire check.
For related trip costs, you can also use the length converter to convert miles to kilometers or vice versa before entering the distance, and the electricity cost calculator if you are comparing a gas vehicle against an EV.
Frequently asked questions
How do I calculate the fuel cost for a road trip?
Divide your trip distance by your MPG to get gallons needed, then multiply by the price per gallon. Example: 400 miles / 28 MPG = 14.3 gallons × $3.50 = $50. For metric, multiply km by L/100km, divide by 100, then multiply by the price per liter.
What is a good MPG?
For a standard gas-powered car, 30+ MPG is good. Above 40 MPG is excellent. Hybrids can reach 50-55 MPG. Trucks and SUVs typically land between 16-25 MPG. The EPA publishes official ratings at fueleconomy.gov for all new vehicles.
How do I convert L/100km to MPG?
Divide 235.214 by your L/100km figure. A car rated at 6.0 L/100km equals 235.214 / 6.0 = 39.2 MPG. A car at 9.0 L/100km equals about 26.1 MPG.
Does the fuel cost calculator work for metric units?
Yes. ToolHQ's fuel cost calculator supports distance in kilometers, fuel efficiency in L/100km, and price per liter. Switch units in the calculator input fields.
How much does the average commute cost in fuel per year?
A 20-mile round-trip commute (10 miles each way) at 28 MPG and $3.50/gallon costs roughly $3.13 per day. Over 250 working days, that is about $781 per year. Longer commutes or lower fuel efficiency can push this above $2,000 per year.
The short version
Your fuel cost is distance divided by efficiency, multiplied by price. It sounds simple, but the numbers add up fast over a year of commuting or frequent road trips. ToolHQ's fuel cost calculator handles both MPG and L/100km, works for one-way and round trips, and gives you the cost per mile or kilometer alongside the total. No account needed, no data stored.
Try the free fuel cost calculator now
For more useful travel and vehicle tools, check the unit converter for distance and volume conversions and the electricity cost calculator if you are weighing the long-term cost of switching to an EV.