Mileage Calculator
Price out the miles before you drive them. Enter the trip distance, your car’s MPG, and the local gas price to get gallons and fuel cost — flip on round trip, then split the total among passengers for a fair carpool share.
Fuel only — tolls, parking, and wear are extra. The IRS-style per-mile rates in our reimbursement calculator include those ownership costs.
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Check it outHow trip fuel cost is estimated
Divide the miles by your MPG to get gallons, multiply by the pump price, and you have the trip’s fuel bill — the marginal cost of driving. Use your car’s real economy (highway trips usually beat the combined figure), and remember the fuel bill is only part of the true cost: tires, oil, and depreciation roughly double the per-mile figure, which is why standard reimbursement rates sit far above pure fuel cost.
For carpools, splitting the round-trip total evenly — including a share for the driver — is the common convention; some groups add a little extra for the driver’s wear and tear.
How it’s calculated
Gallons = distance ÷ MPG (distance doubled for round trips). Fuel cost = gallons × price. Per person = cost ÷ passengers (driver included). Cost per mile = cost ÷ total miles.
Fuel-only estimate. Real economy drops with mountain routes, headwinds, roof boxes, and heavy loads — pad long trips by 5–10%.
Worked example
A 240-mile drive each way at 28 MPG and $3.10/gal uses 8.57 gallons and costs $26.57 one way — $53.14 round trip (17.14 gallons). Split three ways, that’s $17.71 each, and the fuel cost works out to about $0.11 per mile.
Common mistakes
- Using the EPA sticker MPG for a loaded car at 75 mph — real highway economy is often 10–15% lower.
- Forgetting to double for the drive home — the round-trip toggle handles it.
- Splitting only the gas while the driver eats tolls and wear — agree on the deal up front.
- Comparing driving to flying on fuel alone; add tolls, parking, and hours behind the wheel.
Where it is used
- Budgeting road trips, moves, and holiday drives.
- Settling carpool and rideshare-to-the-game money fairly.
- Estimating the fuel piece of visiting clients or job sites.
- Quick sanity check against mileage reimbursement offers.
Frequently asked questions
How much does gas cost per mile?
Gas price ÷ MPG. At $3.10 and 28 MPG that is about 11 cents a mile; a 17-MPG truck at the same price costs 18 cents. Hybrids at 50 MPG drop it to 6 cents.
Should the driver pay a share?
The simplest fair rule: total fuel ÷ everyone in the car, driver included — the driver still contributes the vehicle. Some carpools give the driver a discount or add a per-mile wear allowance instead; what matters is agreeing before the trip.
Why is the IRS mileage rate so much higher than my fuel cost?
The IRS standard rate reimburses total ownership cost — depreciation, insurance, maintenance, and tires — not just fuel. Fuel is typically only a third or less of the per-mile cost of running a car; see our mileage reimbursement calculator for the current rate.
Can I use kilometers and liters?
This page is set up for US units. The fuel cost calculator handles US, metric, and UK units and can also annualize your driving.
How do I estimate MPG for the trip?
Steady highway driving usually beats your combined average by 10–20%, while mountain routes and heavy loads eat that back. If you know your car’s highway figure, use it; otherwise measure a real tank with the gas mileage calculator.