Enter distance, fuel economy and gas price to see what a trip costs. Switch tabs to find your real MPG from a fill-up, work out how far a tank will go, or compare a mileage reimbursement rate with your fuel cost.
This tool runs entirely in your browser. What you enter is never sent anywhere.Your input is never sent anywhere.
DetailsUnits
Switching units converts the numbers you have already typed. The currency symbol is only a label; no exchange rates are applied.
Estimated trip cost
Fuel cost per mi
$0.117
Fuel cost per 100 mi
$11.67
Fuel only
$11.67
Fuel needed
3.33 gal
TIP
Real-world fuel economy is often different from the sticker rating. For a closer estimate, find your own figure on the Real MPG tab and apply it here.
Trip
Fuel Economy & Price
Same as 7.84 L/100km · 12.75 km/L · 30 mpg (US) · 36 mpg (UK)
Vehicle chips are round-number examples, not official ratings. Enter your own car's figure for a better estimate.
The chips are example values, not current averages. Enter the price from your pump or receipt.
How to Calculate Fuel Cost: Distance ÷ MPG × Price
The fuel cost of a trip is distance ÷ fuel economy × fuel price. A 300-mile drive in a car that gets 30 mpg uses 10 gallons, and at $3.50 a gallon that is $35. Your real fuel economy comes from the other direction: distance ÷ fuel added at the pump.
This calculator puts both formulas in four tabs: Trip Fuel Cost, Real MPG (Fill-Up), Mileage Reimbursement, and Range & Fuel Needed. Round trips, tolls and parking, a per-person split, and monthly and yearly totals are on the first tab.
Choose US (mpg, gallons), UK (imperial mpg, liters) or metric (km/L or L/100km) with the Units buttons. Numbers you have already typed are converted when you switch, so you can compare a US mpg rating with a European L/100km figure without doing the math.
Road Trips, Gas Splits, Car Comparisons: Common Uses
Budgeting a road trip
Enter the one-way distance, turn on Round trip, and add tolls and parking to see the full cost before you leave.
Splitting gas money with passengers
Type the number of people in Split between and get a per-person amount that includes tolls and parking if you added them.
Checking if a tank will get you there
On Range & Fuel Needed, enter the fuel you have or the dollars you will spend and see roughly how many miles that covers.
Tracking your real MPG
Log the trip meter distance and the fuel added at each fill-up to see your real-world number and compare it with the rated figure.
Comparing cars before you buy
Switch the vehicle chips or type two MPG figures to compare fuel cost per mile and per 100 miles, or the monthly and yearly cost of a regular drive.
Checking a mileage reimbursement
Enter your monthly business driving and the rate you are paid to see how it compares with what you spend on fuel.
Quick Start: Four Tabs, Four Questions
- Choose your units and currency symbol above the tabs, then enter the distance, fuel economy and fuel price on Trip Fuel Cost. The vehicle chips fill in a sample figure.
- Turn on Round trip, Add tolls & parking or Repeat every week if they apply, and enter the number of people in Split between to see a per-person cost.
- To measure your own fuel economy, open the fill-up tab, enter the distance since your last fill-up and the fuel you added, then send the result to the cost calculation with one click.
- Use Range & Fuel Needed to go from fuel or dollars to distance, or Mileage Reimbursement to compare a per-mile rate with your fuel cost.
Note: Results update as you type. Fuel economy and fuel price are shared across all four tabs.
What Affects the Numbers: Prices, Units and Presets
- Vehicle chips are round-number examples, not EPA ratings. For your own car, use the window sticker, the owner's manual or fueleconomy.gov.
- Fuel price chips are example values, not current averages. Enter the price from the pump or your receipt.
- The fill-up method depends on filling to the same point each time. A partial fill-up skews the result, so average several tanks if you can.
- Switching units converts the distance, fuel, fuel price and fuel economy you have already entered. The currency symbol ($, £, €) is only a label; no exchange rate is applied.
- The IRS business mileage rate shown on the reimbursement tab is 76 cents per mile, effective July 1, 2026 (it was 72.5 cents from January 1 to June 30, 2026). The IRS changes it, so confirm the current rate at irs.gov. This tool is not tax advice.
- All calculations run in your browser. Nothing you enter is sent to a server.
Cost per Mile and per 100 Miles by Vehicle Type
Example fuel costs at $3.50 per gallon. The MPG values are round numbers for illustration, not EPA ratings.
| Vehicle type | Example MPG | Per mile | Per 100 miles | Per 10,000 miles |
|---|---|---|---|---|
| Compact car | 32 mpg | $0.109 | $10.94 | $1,094 |
| Midsize sedan | 30 mpg | $0.117 | $11.67 | $1,167 |
| Minivan | 22 mpg | $0.159 | $15.91 | $1,591 |
| SUV | 25 mpg | $0.140 | $14.00 | $1,400 |
| Pickup truck | 20 mpg | $0.175 | $17.50 | $1,750 |
| Hybrid | 50 mpg | $0.070 | $7.00 | $700 |
How much can fuel economy change the yearly bill?
At $3.50 per gallon, driving 10,000 miles in a 20 mpg pickup costs about $1,750 in fuel, versus about $700 in a 50 mpg hybrid. That is a gap of roughly $1,050 per year.
Gas prices change often. Enter your own MPG and the price you pay in the calculator for a figure that fits your car.
MPG vs km/L vs L/100km: Conversions and Real-World Fuel Economy
Reference notes on fuel economy units, the fill-up method and mileage reimbursement.
Converting MPG, km/L and L/100km
Higher is better for mpg and km/L, but lower is better for L/100km. To convert, divide 235.215 by the US mpg figure to get L/100km (use 282.481 for UK mpg), then divide 100 by L/100km to get km/L.
Example: 30 mpg (US) is about 7.84 L/100km, or about 12.75 km/L. The calculator shows these equivalents under the fuel economy field and on the fill-up tab.
US gallon vs imperial gallon: why UK MPG looks higher
A US gallon is about 3.785 liters and an imperial (UK) gallon is about 4.546 liters, so the imperial gallon is roughly 20% larger. The same car shows a figure about 20% higher in UK mpg: 30 mpg (US) is about 36 mpg (UK).
Fuel in the UK is sold by the liter, so the UK option uses imperial mpg for fuel economy and liters for fuel amounts and price.
Measuring real MPG with the fill-up method
Fill the tank to the first automatic click-off and reset the trip meter. Drive as usual, then refill to the same point and note the gallons added and the trip distance. Divide miles by gallons.
Example: 350 miles on 12 gallons is about 29.2 mpg. Repeat over several tanks, since one tank can be skewed by a long highway run or a cold week. If you do not know the gallons, enter the receipt total and the calculator divides it by your fuel price.
Sticker MPG vs real-world MPG
Ratings on new-car labels come from standardized testing so cars can be compared on equal terms. Your own number depends on speed, temperature, A/C use, terrain, cargo, tire pressure and driving style. Ratings by model are listed at fueleconomy.gov.
Enter the rating under Rated fuel economy on the fill-up tab to see your result as a percentage of it.
Mileage reimbursement vs your actual fuel cost
For business driving, the IRS publishes a standard mileage rate each year, and many employers use it as a per-mile reimbursement. In 2026 the business rate was 72.5 cents per mile from January 1 and 76 cents per mile from July 1, so 500 miles at 76 cents is $380.
That rate is meant to reflect the cost of operating a vehicle, not only fuel. At 30 mpg and $3.50 per gallon, fuel is about 12 cents per mile, roughly 15% of a 76-cent rate. The rest goes toward things like insurance, maintenance and depreciation. This page is not tax advice; check IRS guidance for how the rate applies to you.
Why Estimates Miss: Five Mistakes to Avoid
Using the sticker rating for a long trip and underestimating the bill
The rating on a window sticker comes from standardized testing. Highway speed, hills, a loaded trunk, a roof box or A/C can push real consumption higher, so the trip can cost more than the estimate.
💡 See the solution▼
Mixing up US and UK gallons
An imperial (UK) gallon is about 20% larger than a US gallon, so the same mpg figure means different things on each side. Typing a UK mpg figure into a US gallon price makes the cost look too low.
💡 See the solution▼
Forgetting the drive home
Entering only the outbound distance cuts the fuel cost roughly in half, and tolls or parking at the destination are often left out.
💡 See the solution▼
Typing L/100km as if it were km/L or MPG
A figure like 7.8 is a good L/100km result but would be a very poor km/L or mpg number. Entered under the wrong unit, it produces a cost that is far too high.
💡 See the solution▼
Treating a mileage rate as profit
A per-mile rate that looks high next to fuel alone also has to pay for insurance, maintenance and depreciation. Comparing it only with gas can make it look like extra income.
💡 See the solution▼
Gas Mileage and MPG: Common Questions
Q.How do you calculate gas cost for a trip?
A. Divide the distance by your fuel economy to get the fuel you will use, then multiply by the price per gallon. For a 300-mile trip in a car that gets 30 mpg, that is 300 ÷ 30 = 10 gallons. At $3.50 per gallon, the trip costs about $35. The calculator does this as you type and adds tolls, parking and a round-trip option if you need them.
Q.How much does it cost to drive 100 miles?
A. It depends on fuel economy and gas price. At $3.50 per gallon, 100 miles costs about $17.50 in a 20 mpg pickup, about $11.67 at 30 mpg, and about $7.00 at 50 mpg. The calculator shows the fuel cost per mile and per 100 miles for your own numbers, so you can compare cars or fuel prices.
Q.How do I calculate my real MPG?
A. Use the fill-up method. Fill the tank to the first automatic click-off, reset the trip meter, and drive as usual. At the next fill-up, top off to the same point, then divide the miles driven by the gallons added. For example, 350 miles on 12 gallons is about 29.2 mpg. If you do not know the gallons, enter the receipt total and the calculator divides it by your gas price.
Q.How do I convert MPG to L/100km or km/L?
A. To get L/100km, divide 235.215 by the US mpg figure (use 282.481 for UK mpg). To get km/L, divide 100 by the L/100km figure. For example, 30 mpg (US) is about 7.84 L/100km, or about 12.75 km/L. Higher is better for mpg and km/L, but lower is better for L/100km. The calculator shows all of these under the fuel economy field.
Q.Why is UK MPG higher than US MPG?
A. The two countries use different gallons. A US gallon is about 3.785 liters and an imperial (UK) gallon is about 4.546 liters, which is roughly 20% larger. The same car therefore gets a higher number in UK mpg. A car rated at 30 mpg (US) is about 36 mpg (UK). Pick the UK or US option in the Units buttons so the right gallon is used.
Q.How far can I drive on a tank or a set amount of gas?
A. Multiply the fuel by your fuel economy. Ten gallons at 30 mpg is about 300 miles. For a dollar amount, divide it by the gas price first: $40 at $3.50 per gallon buys about 11.4 gallons, which is about 343 miles at 30 mpg. The Range & Fuel Needed tab does both calculations, and also works out how much fuel and money a given distance requires.
Q.How do I split gas money for a road trip?
A. Work out the total, including tolls and parking if you want to share them, then divide by the number of people. A $35 trip split four ways is $8.75 each. Enter the number of people in the Split between field on the Trip Fuel Cost tab and the per-person amount appears with the total.
Q.How is mileage reimbursement calculated, and what is the IRS rate?
A. Multiply the business miles by the per-mile rate. The IRS business standard mileage rate for 2026 was 72.5 cents per mile from January 1 and was raised to 76 cents per mile from July 1, so 500 business miles at 76 cents is $380. The rate is meant to cover more than fuel, so the calculator compares it with your fuel-only cost. Rates change, so check irs.gov for the current figure. This is not tax advice.
Q.Why is my real MPG lower than the sticker rating?
A. The rating comes from standardized testing, while your driving depends on speed, temperature, A/C use, hills, cargo, tire pressure and how you accelerate and brake. Short trips and stop-and-go traffic tend to lower the number. On the fill-up tab you can enter the rated figure to see your result as a percentage of it. Ratings by model are listed at fueleconomy.gov.
Q.Are the numbers I enter saved or sent anywhere?
A. No. The calculations run in your browser. Nothing you type is uploaded or stored, and the values are cleared when you close or reload the page.
Your feedback
makes this tool better.
Tell us which features you'd like, what should be fixed, or which new tool you'd like to see. An engineer reads every submission and uses it to guide development.