How to use the gas trip calculator
- Enter the one-way distance in miles or kilometers (from your maps app), and tick round trip if you're coming back.
- Enter your fuel economy: US mpg, UK mpg, L/100 km or km/L.
- Enter the gas price per gallon or per liter.
- Optionally, enter how many people are splitting the cost, and the number of trips (for a commute or repeated drive).
- Read the total fuel cost, the fuel needed, the cost per person and per mile, and how the total changes if gas costs more or less.
How to calculate gas cost for a trip
Gas cost = distance ÷ mpg × price per gallon. For a 350-mile drive in a car that gets 25 mpg, with gas at $3.50 a gallon:
- Fuel needed: 350 ÷ 25 = 14.0 gallons
- Cost: 14.0 × $3.50 = $49.00
- Cost per mile: $49.00 ÷ 350 = $0.14
In metric: liters = km × L/100 km ÷ 100, then multiply by the price per liter. A 500 km trip at 7 L/100 km uses 35.0 liters.
Round trips and splitting gas money
A round trip doubles the distance, and so the fuel. Splitting evenly between everyone in the car is the simplest fair split. Example: 270 miles each way at 30 mpg and $3.50 a gallon is 540 miles, 18.0 gallons and $63.00 in gas, or $21.00 each for three people.
Gas cost per mile chart
Fuel cost per mile by fuel economy and gas price. Multiply by your distance for a quick estimate.
| MPG | $3.00/gal | $3.50/gal | $4.00/gal | $4.50/gal | $5.00/gal |
|---|---|---|---|---|---|
| 15 mpg | $0.20 | $0.23 | $0.27 | $0.30 | $0.33 |
| 20 mpg | $0.15 | $0.18 | $0.20 | $0.23 | $0.25 |
| 25 mpg | $0.12 | $0.14 | $0.16 | $0.18 | $0.20 |
| 30 mpg | $0.10 | $0.12 | $0.13 | $0.15 | $0.17 |
| 35 mpg | $0.09 | $0.10 | $0.11 | $0.13 | $0.14 |
| 40 mpg | $0.08 | $0.09 | $0.10 | $0.11 | $0.13 |
| 50 mpg | $0.06 | $0.07 | $0.08 | $0.09 | $0.10 |
Gas cost for popular road trips
One-way fuel cost at 25 mpg and $3.50 a gallon, using approximate driving distances. Enter your own route, car and price above for your real number.
| Route | Miles (approx.) | Gallons | Gas cost |
|---|---|---|---|
| New York, NY → Washington, DC | 225 | 9.0 | $31.50 |
| Dallas, TX → Houston, TX | 240 | 9.6 | $33.60 |
| Los Angeles, CA → Las Vegas, NV | 270 | 10.8 | $37.80 |
| Chicago, IL → Detroit, MI | 280 | 11.2 | $39.20 |
| San Francisco, CA → Los Angeles, CA | 380 | 15.2 | $53.20 |
| Atlanta, GA → Orlando, FL | 440 | 17.6 | $61.60 |
| New York, NY → Chicago, IL | 790 | 31.6 | $110.60 |
| Los Angeles, CA → New York, NY | 2,790 | 111.6 | $390.60 |
How to spend less on gas on a road trip
- Slow down a little. Fuel economy usually drops quickly above 55-60 mph; cruising at 65 instead of 75 can save 10-15%.
- Check tire pressure before you leave. Under-inflated tires waste fuel and wear faster.
- Pack light and skip the roof box if you can: weight and drag both cost mpg.
- Fill up before you reach the highway: stations right off major interstates and in cities are often the most expensive.
- Take the more efficient car if you have a choice; the chart above shows what a 10 mpg difference is worth per mile.
More car tools
- Tire size calculator: bigger tires change your odometer, and the mpg your trip computer reports.
- Speedometer calculator: correct your speed and mileage after a tire size change.
Frequently asked questions
How do I calculate the gas cost for a trip?
Divide the distance by your car's miles per gallon to get the gallons needed, then multiply by the price per gallon. For a 350-mile trip at 25 mpg with gas at $3.50: 350 ÷ 25 = 14.0 gallons, × $3.50 = $49.00. Double the distance for a round trip.
How much gas does it take to drive 500 miles?
At 25 mpg, 500 miles uses 20.0 gallons, which is $70.00 at $3.50 a gallon. At 35 mpg it's about 14.3 gallons; at 18 mpg (a big SUV or pickup) about 27.8 gallons.
How much should I charge friends for gas on a road trip?
The usual way is to split the fuel cost evenly between everyone in the car, driver included. A 270-mile trip each way (540 miles round trip) at 30 mpg and $3.50 a gallon costs $63.00 in gas, so $21.00 each for three people. Some groups also add tolls and parking, or let the driver pay less because it's their car.
What MPG should I use?
Use your car's highway mpg for road trips and the combined figure for mixed driving. You can find the official ratings on fueleconomy.gov or your window sticker, but your own average (miles driven ÷ gallons to refill) is more accurate. Heavy loads, roof boxes, towing, high speeds and cold weather can all lower it by 10-30%.
How do I convert L/100 km to mpg?
US mpg = 235.21 ÷ L/100 km. So 7 L/100 km is about 33.6 mpg, and 25 mpg is about 9.4 L/100 km. The calculator accepts US mpg, UK (imperial) mpg, L/100 km and km/L, and converts for you.
How much does it cost to commute to work?
Enter your one-way distance, tick round trip and set the number of trips to your working days. A 15-mile commute each way at 28 mpg and $3.50 a gallon, 21 working days a month, is 630 miles and about $78.75 a month in gas.
Does this work in kilometers and liters?
Yes. Switch the distance to km, the fuel economy to L/100 km or km/L, and the price to per liter. A 500 km trip at 7 L/100 km uses 35.0 liters; at 1.80 a liter that costs 63.00 in your currency.
Does the calculator know current gas prices?
No. Prices change daily and vary by state and station, so enter the price you expect to pay. Check a gas price app or the pump near your route, and use the "what if gas costs more or less" table to see how much a price swing changes the trip.
Is my data saved or sent anywhere?
Your entries are saved only in your own browser so they are there next time. Nothing is sent to our servers.