Skip to content

Road Trip Calculator

TravelRoad Trips and Distance
Route and speed
Units

Use the route distance from your map app, not the straight-line distance.

Moving average including towns and traffic, usually below the highway limit.

Car and fuel
Stops and travellers
Fuel cost for the trip —
Distance driven
—
Fuel needed (gal or L)
—
Time at the wheel
—
Rest stops
—
Door-to-door time
—
Fuel cost per person
—

A road trip's fuel cost is the distance divided by your car's mpg, times the fuel price. A 300-mile drive at 25 mpg burns 12 gallons; at $3.50 that is $42.00. At 60 mph it takes 5 hours of driving, and two 15-minute stops make it 5 h 30 min door to door.

About this tool

Planning a drive means answering three questions at once: how much fuel will it take, what will that fuel cost, and when will you arrive. This calculator takes the route distance, your average moving speed, the car's fuel economy and the local pump price, then adds rest stops at a regular interval. It returns the fuel bill, the gallons or litres needed, hours behind the wheel, door-to-door time and the share each passenger pays if you split the fuel. Tick round trip to double the distance for an out-and-back drive. It works in US units (miles, mpg, gallons) or metric (kilometres, L/100 km, litres). The figures are planning estimates: tolls, parking, city detours, air conditioning and heavy loads are not included, and real fuel use on hilly or fast highway routes often runs above the rated figure.

How to use it

  1. Pick units and enter the route

    Choose US or metric, type the one-way road distance from your map app and tick round trip if you are coming back the same way.

  2. Set an honest average speed

    Use the moving average for the whole route, including towns and traffic, not the speed limit.

  3. Add the car and fuel price

    Enter mpg or L/100 km and the price per gallon or litre you expect to pay on the way.

  4. Plan stops and travellers

    Set how often you stop and for how long, and use the + and − buttons for the number of people splitting fuel.

Examples

300 miles at 25 mpg, two people

Units
US (mi, mpg, gal)
One-way distance
300
Round trip (drive back the same way)
No
Average speed
60
Fuel economy
25
Fuel price per gallon or litre
3.5
Rest stop every
2
Length of each stop
15
People sharing the fuel cost
2

Result Fuel cost for the trip: 42.00
Distance driven: 300
Fuel needed (gal or L): 12
Time at the wheel: 5 h
Rest stops: 2
Door-to-door time: 5 h 30 min
Fuel cost per person: 21.00

  1. Distance driven = 300 mi × 1 = 300 mi
  2. Fuel = 300 mi ÷ 25 mpg = 12 gal
  3. Fuel cost = 12 gal × 3.5 = 42
  4. Driving time = 300 ÷ 60 = 5 h (5 h 0 min)
  5. Rest stops = 2 × 15 min; total time = 5 h 30 min

Five hours of driving with a 15-minute stop after hours 2 and 4 makes 5 h 30 min door to door; the $42 of fuel splits to $21 each.

250 km there and back, 7 L/100 km

Units
Metric (km, L/100 km)
One-way distance
250
Round trip (drive back the same way)
Yes
Average speed
90
Fuel consumption
7
Fuel price per gallon or litre
1.8
Rest stop every
2
Length of each stop
20
People sharing the fuel cost
4

Result Fuel cost for the trip: 63.00
Distance driven: 500
Fuel needed (gal or L): 35
Time at the wheel: 5 h 33 min
Rest stops: 2
Door-to-door time: 6 h 13 min
Fuel cost per person: 15.75

  1. Distance driven = 250 km × 2 = 500 km
  2. Fuel = 500 km × 7 L/100 km ÷ 100 = 35 L
  3. Fuel cost = 35 L × 1.8 = 63
  4. Driving time = 500 ÷ 90 = 5.56 h (5 h 33 min)
  5. Rest stops = 2 × 20 min; total time = 6 h 13 min

500 km at 7 L/100 km burns 35 L; at 1.80 a litre that is 63.00, or 15.75 for each of four passengers.

How it is calculated

Fuel = D ÷ mpg (US) or D × c ÷ 100 (metric); Cost = Fuel × P; Drive time = D ÷ v; Stops = ceil(drive time ÷ k) − 1

D
distance driven, doubled for a round trip
c
fuel consumption in litres per 100 km
P
fuel price per gallon or litre
v
average moving speed
k
hours of driving between rest stops

Fuel follows the trip-cost method used by fueleconomy.gov: divide miles by miles per gallon, or multiply kilometres by litres per 100 km and divide by 100. Driving time is distance over average speed. A stop is counted each time the driving clock passes a full interval before arrival, so a 5-hour drive with a stop every 2 hours gets two stops, not three. Door-to-door time is driving time plus all stop minutes.

When not to use it

  • Electric cars need kWh per mile and a charging price, not mpg and a pump price.
  • Multi-day trips with hotel nights are better planned leg by leg.
  • Routes with ferries or long toll sections carry costs this sheet leaves out.

Common mistakes

  • Using the highway speed limit as the average speed, which makes arrival times far too early.
  • Entering straight-line distance instead of the road distance from a map route.
  • Forgetting to tick round trip when the car comes back the same way.

Frequently asked questions

How do I work out fuel cost for a road trip by hand?

Divide the miles by your car's mpg to get gallons, then multiply by the price per gallon. For 450 miles at 30 mpg and $3.20 a gallon: 450 ÷ 30 = 15 gallons, and 15 × $3.20 = $48.00. In metric, multiply kilometres by L/100 km and divide by 100 to get litres.

What average speed should I use?

Use a moving average for the whole route, not the limit. On US interstates with light traffic 60 to 65 mph is typical; mixed routes through towns often average 45 to 50 mph. Map apps give a drive time you can divide into the distance to get a realistic figure.

How are rest stops counted?

A stop is added every time your driving clock completes the interval you set, as long as you have not already arrived. A 7-hour drive with a stop every 2 hours gets stops at hours 2, 4 and 6, so three stops. Setting the stop length to 0 removes them.

Why does my real fuel use come out higher than the estimate?

Rated mpg is measured on standard test cycles. Speeds above about 60 mph, roof boxes, full luggage, air conditioning and mountain grades all raise consumption, often by 10 to 25 percent. Entering a slightly lower mpg than the sticker gives a safer budget.

Can I convert mpg to L/100 km?

Yes: L/100 km = 235.21 ÷ US mpg. A car rated 30 mpg uses about 7.8 L/100 km. If your car shows one figure and you prefer the other unit system, convert first and then switch the units option.

How is the cost per person split?

The fuel bill is divided equally by the number of people you set with the stepper. It covers fuel only; tolls, parking and snacks are not part of the share.

Cite this tool

Using this tool in an assignment, article or report? Copy a citation, or a link for your website.

APA

Tools Directory Editorial Team. (2026, October 14). Road Trip Calculator. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/travel/road-trips-and-distance/road-trip-calculator/

MLA

Tools Directory Editorial Team. “Road Trip Calculator.” Tools Directory, 14 Oct. 2026, https://tools.milunir.com/travel/road-trips-and-distance/road-trip-calculator/. Accessed 26 Oct. 2026.

Chicago

Tools Directory Editorial Team. “Road Trip Calculator.” Tools Directory. Last modified October 14, 2026. Accessed October 26, 2026. https://tools.milunir.com/travel/road-trips-and-distance/road-trip-calculator/.

Link<a href="https://tools.milunir.com/travel/road-trips-and-distance/road-trip-calculator/">Road Trip Calculator – Tools Directory</a>