Trip Cost Calculator
Estimate the full cost of a car journey using fuel economy or EV efficiency, energy prices, return distance, repeated trips, tolls, parking and other charges. See the cost per mile, cost per traveller and a sensible budget allowance.
Reviewed .
Estimate, not a route quotation
Results depend on the distance and prices you enter. Actual costs can change with traffic, diversions, weather, driving style, vehicle load, heating or air-conditioning use, charging losses and local road charges. Check your route, vehicle display and current tariffs before travelling.
Calculate your trip cost
Enter figures for one journey, then use the return and repeat settings where needed.
1. Journey
Use the planned route distance, not straight-line distance.
Choose miles or kilometres.
A return journey doubles the one-way distance.
Useful for commuting or repeated visits.
Includes the driver where appropriate.
Optional buffer for price or route changes.
2. Vehicle and energy
Use a realistic figure for your normal driving.
UK mpg uses an imperial gallon.
Enter the price you expect to pay.
Price per litre.
Use your car's recent average where possible.
Match the unit shown by your vehicle.
Use the home or public tariff for this journey.
Price per kWh.
Optional allowance above battery energy.
Petrol, diesel or hybrid
Electric vehicle
3. Optional costs
Enter the total charge for one complete trip. For example, include both directions of any tolls when calculating a return journey. These amounts are multiplied only when “identical trips” is greater than one.
What this calculator includes
Journey distance
One-way or return distance, multiplied by the number of identical journeys you plan to make.
Vehicle energy
Petrol, diesel and hybrid calculations using UK mpg, L/100 km or km/L, plus EV calculations using mi/kWh or kWh/100 km.
Journey-specific charges
Tolls, parking, road-user or clean-air charges, ferries and other costs entered by the user.
Sharing and contingency
Cost per traveller and an optional budget allowance for small route or price changes.
It does not automatically include depreciation, finance, insurance, servicing, tyres, tax or the value of the driver's time. Those are broader ownership costs rather than direct cash costs for one trip.
How the calculation works
The calculator first converts the entered distance into miles and kilometres. A return journey doubles the one-way distance, and the result is then multiplied by the number of identical trips.
UK mpg
The UK imperial gallon is 4.54609 litres. Fuel cost is litres multiplied by price per litre.
L/100 km or km/L
Electric vehicle
Any charging overhead is added before multiplying by the charging rate.
Worked example
A driver plans a 180-mile journey each way, selects a return trip and expects 45 UK mpg. Fuel is entered at £1.45 per litre. The complete trip also has £6.50 of tolls and £12 parking, shared by three travellers.
The total distance is 360 miles. Estimated fuel use is about 36.37 litres:
Fuel costs about £52.73. Adding £18.50 of other charges gives an estimated total of £71.23, or approximately £23.74 per traveller.
Why the real cost may differ
Official versus real economy
Laboratory or advertised figures may differ from everyday driving. A recent trip-computer average can be more useful for personal budgeting.
Traffic and driving conditions
Repeated acceleration, congestion, steep gradients, strong winds and poor weather can increase energy use.
Vehicle load and accessories
Passengers, luggage, roof boxes, heating and air conditioning can affect fuel or electricity consumption.
EV tariff and charging overhead
Home, destination and rapid-charging tariffs can differ considerably. Energy drawn from the charger can also exceed energy added to the battery.
Practical ways to reduce journey costs
Use realistic economy data
Check your recent average rather than relying only on a best-case advertised figure.
Check tyre pressures
Use the vehicle manufacturer's recommended pressures, especially before a long or heavily loaded journey.
Drive smoothly and legally
Anticipating traffic and avoiding unnecessary acceleration and braking can reduce fuel or energy use.
Compare charging and fuel locations
Prices can vary by forecourt, home tariff, public charger and charging speed. Enter the rate you genuinely expect to use.
Check charges before departure
Confirm tolls, parking restrictions, clean-air rules and ferry prices for the specific route and travel date.
Share costs transparently
Use the per-traveller result as a starting point and agree whether parking or other personal expenses are included.
Common questions
Does a return journey automatically double every cost? ⌄
Should I use official MPG or my trip-computer average? ⌄
Does UK mpg use an imperial or US gallon? ⌄
Which electricity price should I use for an EV? ⌄
What does the charging-overhead field do? ⌄
Does cost per person mean passengers must pay equally? ⌄
Are servicing, depreciation and insurance included? ⌄
Sources and assumptions
This calculator is a budgeting tool. It applies the formulas shown on this page to the figures entered by the user; it does not retrieve a route, live fuel price, live charging tariff or current road charge.
- Distance conversion: 1 mile is treated as 1.609344 kilometres.
- UK gallon conversion: 1 UK imperial gallon is treated as 4.54609 litres.
- Return journeys: selecting return doubles the entered one-way distance.
- Repeated trips: distance, energy use and optional costs for one complete trip are multiplied by the number of identical trips.
- Fuel and charging prices: no default price is presented as current. Users should enter a recent price or tariff applicable to their journey.
- Real-world economy: actual consumption can differ from official test values because of route, weather, load, driving style and vehicle condition.
- Budget allowance: the optional percentage is shown separately as a planning figure and does not change the base estimated cost.
Useful official references
Results are estimates for general information and budgeting. Check current route restrictions, tolls, parking fees, clean-air or road-user charges, ferry prices, fuel prices and charging tariffs directly with the relevant provider before travelling.