Free Fuel Cost Calculator

Fuel Cost Calculator for Trips and Fleets

Estimate the fuel cost of a trip from distance, fuel economy and price. For a business with vehicles, explore an annual fleet model with editable assumptions.

No email gateTransparent assumptionsTrip costs and annual fleet estimates

Calculate fuel cost for a trip

Enter your journey distance, your vehicle’s fuel consumption and the price per litre. See the fuel cost immediately, with an optional return journey.

Estimated fuel cost

Enter three positive values to see your trip cost.

Fuel only. Tolls, parking, charging, vehicle wear and currency conversion are excluded. Use the currency in which your fuel price is quoted. UK MPG uses an imperial gallon.

Plan annual fuel costs for a business fleet

[01]

Your Fleet Model

Your Inputs

Build your fleet baseline

Add your fleet size and fuel price to see your estimate. Adjust the pre-filled mileage and fuel efficiency if needed.

Fleet and fuel

Units
Currency
Fine-tune the model

Adjust the operating costs and savings assumptions to match your business.

Estimated Annual Value

What your fleet could recover

Your estimate appears here

Enter your fleet size and fuel price. If your card count needs a custom plan, add the monthly quote to see your estimate.

[02]

Transparent by design

A fuel cost calculator that shows its working.

A fleet fuel cost calculator estimates annual fuel spend from vehicle count, distance, fuel economy and price per litre. This model then separates direct cash savings from productivity value, so cheaper fuel is never mixed invisibly with time savings.

Fuel cost formula

Annual distance per vehicleAverage fuel efficiencyAverage fuel price per litreCurrent annual fuel cost

In UK units: annual fuel cost = (annual miles ÷ MPG) × 4.54609 × price per litre. Example: a 20-vehicle fleet driving 20,000 miles each at 32 MPG pays about £80,000 a year with petrol at £1.40 per litre.

ConservativeAverageCutting-edge

Three honest scenarios

A single optimistic number hides uncertainty. Conservative, average and cutting-edge cases vary each saving lever independently and keep optional behaviour savings off until you choose to include them.

Fuel-price assumption

Rally customers save more than 5% on fuel on average. The model uses 3% in the conservative case, 5.5% in the average case and 8% in the cutting-edge case to show a wider honest range.

Rally cost, included

The model assumes one card per vehicle and deducts the published flat monthly plan fee across the year, excluding VAT. Custom plans require your monthly quote. Service-fee savings only cover the current network, transaction and service fees you enter.

Every lever, across all three cases

These are the model's reduction or prevention rates. Your inputs stay constant while the assumptions change, making the range easy to audit.

Every lever, across all three cases
Savings leverConservativeAverageCutting-edge
Cheaper open-loop fuel3%5.5%8%
Potential fee reduction75%90%100%
Less detour fuel40%65%85%
Fuel fraud and misuse25%50%75%
Spend-control behaviour0.5%1.5%3%
Admin and reporting25%50%70%
Fewer accounting errors50%75%90%
card-wait days avoided50%80%100%
Methodology reviewed July 2026.

[03]

Eight value levers

Savings are more than pence per litre.

Closed networks, manual reporting and slow card replacement create costs outside the headline fuel price. The calculator keeps each lever visible.

Open-loop fuel prices

Drivers can choose lower pump prices instead of being routed to one network or a provider-set list price.

No hidden service fees

Model network, transaction and service charges separately from Rally's flat monthly plan fee.

Wider coverage

More accepted stations means fewer detours, fewer declined transactions and less driver frustration.

Fuel fraud controls

Real-time limits and transaction visibility can reduce misuse without assuming every suspicious transaction disappears.

Optional behaviour change

Limits and feedback may change purchasing habits, but this lever stays off until you explicitly include it.

Cleaner accounting

Receipt capture and automated coding reduce the corrections hidden inside month-end close.

Faster card access

Apple Pay can reduce dependence on physical-card shipping for supported drivers and use cases.

Reporting time

One fleet ledger replaces exports, invoice matching and repeated reporting across providers.

[04]

Questions

Fuel Cost Calculator FAQs

Fuel Cost Calculator FAQs

Multiply annual distance by the number of vehicles, convert distance and fuel economy into litres used, then multiply by the average price per litre. In UK units the formula is miles divided by MPG, multiplied by 4.54609 litres per UK gallon and then by fuel price.

Results depend on pump or list prices, fees, routes and controls. Rally customers save more than 5% on fuel on average. The calculator uses three scenarios: 3% conservative, 5.5% average and 8% cutting-edge. It does not promise a guaranteed result.

Yes. The model assumes one card per vehicle and deducts the published monthly fee for the plan that includes that card count, excluding VAT. For a custom plan, enter your monthly quote. The annual cost is the monthly plan fee multiplied by twelve, shown as a separate negative line.

Cheaper fuel and removed fees affect cash directly. Admin and driver time only become financial value when your team can redeploy those hours, so the calculator reports them separately before combining them into total annual value.

A wider acceptance network reduces detours to an approved station. That can save fuel, vehicle wear and paid driver time while making routes less frustrating for employees.

You enter the share of fuel spend you believe is lost to fraud or misuse. The model assumes only 25% of that leakage is prevented in the conservative case, 50% in the average case and 75% in the cutting-edge case.

Yes. Switch the calculator from miles and MPG to kilometres and L/100km. You can also switch between pounds and euros.

No. It is an illustrative planning model. Actual savings depend on fuel prices, routes, fleet adoption, current fees, driver behaviour and the accuracy of the data you enter.

Divide the price in pence per litre by your MPG and multiply by 4.54609. At £1.40 per litre and 32 MPG, fuel costs about 19.9 pence per mile. This calculator reports cost per mile automatically from your fleet's own efficiency and fuel price.

Yes. Enter your fleet's real average fuel efficiency — for example roughly 40 MPG for diesel vans or 8 to 10 MPG for HGVs — and every cost and saving lever scales with it. Mixed fleets can use a weighted average.

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Turn the model into a real plan

See where your fleet is actually leaking value.

Bring your current fuel-card statement and route profile. Rally will validate the assumptions, identify avoidable fees and build a savings plan around your real fleet.

Review my savings with Rally