How do I calculate a trip with gas and tolls?

Divide miles by MPG, multiply by gas price, then add tolls, parking, ferry fees, or other route costs.

Should tolls be added per direction?

Use the total toll amount for the trip you are budgeting. For a round trip, include tolls in both directions when they apply.

Route budget

Trip calculator for gas and tolls

Gas is only part of the cost of a drive. Use this guide to combine fuel, tolls, parking, ferry fees, and route extras into one trip budget.

Use the live calculator Road trip cost page

Gas and toll formula

Total trip cost = miles / MPG x gas price + tolls + parking + extras

For a 180-mile route in a 30 MPG car at $3.60 per gallon, fuel is about $21.60. Add $18 in tolls and $12 in parking, and the trip budget becomes about $51.60.

What to include

Fuel: distance, MPG, and local gas price.
Tolls: bridge, tunnel, express lane, turnpike, and pass charges.
Parking: destination parking, hotel parking, or event parking.
Extras: ferry fees, paid road access, or route permits.

One-way vs round-trip estimates

Use one-way miles when you only need the cost to reach the destination. Use round-trip miles when you need the full travel budget. Tolls are often asymmetric, so check both directions before copying the same toll number twice.

If you are comparing route options, run the shorter route and the lower-toll route separately. A route with more miles can still be cheaper if it avoids expensive toll segments.

Gas and toll trip FAQ

Does this replace a toll authority estimate?

No. Use toll authority or map estimates for exact toll prices, then enter that total into the calculator extras field.

How do I compare two routes?

Run each route with its own distance, gas cost, and toll amount. Compare the total cost and the time difference before deciding.