Monthly Gas Usage Calculator

Estimate how much gasoline your car uses each month and what it may cost. Adjust your driving, MPG, and local gas price to see the results update instantly.

Before calculating: Review all fields. Any prefilled numbers or default selections are starting examples, not verified personal details; update them to match your situation. Complete any fields left blank.

Your driving details

Daily miles drivenEnter your typical miles on a day you drive.

Vehicle MPGUse your vehicle's combined city/highway MPG.

Gas price per gallon ($)Enter the price you pay per gallon, or Look up gas prices near you ↗

Days driven per monthCount the days you typically use your car each month.

Find your car's MPGEnter your year, make and model to check published fuel-economy ratings.

Look up my car's MPG on Google ↗

Your monthly estimate

Estimated monthly fuel cost

$112.50

At the gas price you entered

Monthly miles900 miDaily miles × driving days

Gasoline used32.1 galMonthly miles ÷ MPG

Yearly fuel cost$1,350.00Monthly fuel cost × 12

Cost per mile$0.13Fuel cost ÷ monthly miles

Estimates use your entries and a 30-day month by default. Real-world fuel economy varies with traffic, weather, speed and driving style.

How to use this calculator

Enter your average daily miles, vehicle fuel economy, and the number of days you drive in a typical month. Add the current price per gallon to estimate monthly and yearly fuel costs. The gas price is optional; if you leave it blank, the calculator still estimates miles and gallons.

How monthly gas usage is calculated

Monthly miles = daily miles × days driven per month. Monthly gallons = monthly miles ÷ vehicle MPG. Monthly fuel cost = monthly gallons × gas price per gallon. Yearly fuel cost is estimated by multiplying the monthly cost by 12.

Example calculation

Driving 30 miles per day for 30 days at 28 MPG uses about 32.1 gallons per month. At $3.50 per gallon, the estimated monthly fuel cost is about $112.50. Actual costs depend on driving conditions and fuel prices.

Frequently asked questions

Does the calculator update automatically?
Yes. Results update as you change any of the numeric inputs.

What if I don't know my car's MPG?
Enter your year, make and model in the lookup field and open a Google search for published fuel-economy information. Confirm the result matches your engine and trim.

Is the gas price required?
No. Leave it blank to see monthly miles and gallons without estimating cost.

Why might my actual fuel use be different?
Traffic, speed, weather, tire pressure, vehicle condition, load and driving style all affect real-world MPG.