TripFuel

Fuel Cost for a Trip

Distance, MPG, and gas price — the total fuel bill for your next road trip.

Trip distance (miles)

Car's MPG

Gas price ($/gallon)

Estimated fuel cost

$53

What you entered

Distance: 450 miMPG: 30Gas price: $4

1
Gallons needed for the trip
450 ÷ 30 MPG= 15.00 gal
2
Fuel cost
15.00 × $3.5= $52.50

Result

Fuel cost: $53

A 450-mile trip at 30 MPG and $4/gallon costs about $53 in fuel.

Road trip fuel cost by distance and MPG at $3.50 a gallon

Distance divided by MPG gives the gallons, and gallons times the pump price gives the total. All figures use gas at 3.50 a gallon and are one-way, so double the distance for a return journey before comparing.

Trip distance (miles)	Gallons at 30 MPG	Cost at 20 MPG	Cost at 30 MPG	Cost at 40 MPG
100	3.3	$18	$12	$9
200	6.7	$35	$23	$18
300	10.0	$53	$35	$26
500	16.7	$88	$58	$44
750	25.0	$131	$88	$66
1,000	33.3	$175	$117	$88
1,500	50.0	$263	$175	$131
2,000	66.7	$350	$233	$175
3,000	100.0	$525	$350	$263

Doubling the pump price doubles every cost in the table, so scale the column that matches your car: at 4.20 a gallon multiply by 1.2, at 2.80 multiply by 0.8. Use your highway MPG for interstate driving, and blend it toward the city figure if a large part of the route is urban. A loaded car, a roof box, a headwind, mountains, air conditioning and sustained speeds above 70 mph all cut real economy, so add a margin of 10 to 15 percent to these totals for a genuinely long drive. Illustrative fuel cost only, with no tolls, parking or food.

Three numbers, one total

Distance divided by MPG gives gallons needed, and gallons times price per gallon gives the total cost — a simple chain calculation that's easy to get wrong doing quick mental math, especially over long trip distances.

Why it's worth checking before a long drive

Knowing the real fuel cost upfront helps with trip budgeting and makes it easier to fairly split gas costs when traveling with others.

Frequently asked questions

My road trip is 600 miles, my car gets 28 MPG, and gas is $3.50/gal — what will fuel cost?

About $75. That's 600 / 28 = 21.4 gallons needed, times $3.50 = $75. Split between 3 people, that's $25 each for gas.

How do I estimate gas cost for a round trip?

Double the one-way distance before entering it into the calculator. A 300-mile one-way trip is 600 miles round trip — at 25 MPG and $3.50/gal, that's 24 gallons and $84 total.

Should I use highway or city MPG for a road trip?

Use highway MPG for interstate driving. If your route includes significant city driving, blend the two — a 70% highway / 30% city mix is a reasonable estimate for most road trips. Your car's actual MPG from the MPG calculator is the best input.