How to Calculate Fleet Cost per Kilometre (and Total Cost of Ownership)

Ask most fleet owners what a kilometre costs them and you will get the fuel price. Fuel matters, but it is often well under half the true figure. Cost per kilometre (CPK) — and the total cost of ownership (TCO) behind it — is the single number that tells you which vehicles make money, what to charge a customer, and when to replace a truck. This guide gives you the formula, the cost lines that belong in it, a worked example in Rand, and the mistakes that make most CPK figures wrong.

1. The cost per kilometre formula

At its simplest:

The power comes from splitting the total into costs that move with distance and costs that don’t:

That split explains most surprises. A truck that sits in the yard for a month still depreciates, still needs insurance, and its driver is still paid — so its cost per kilometre rises even though it is spending less on fuel. The formula works the same in any currency and in miles; just keep units consistent.

2. What to include

Fixed costs (time-based)

• Depreciation — (purchase price − expected residual value) ÷ years in service. Use a realistic residual, not the accountant’s tax rate.
• Cost of finance — interest on the vehicle loan or lease, or the opportunity cost of cash tied up in the vehicle.
• Insurance — premiums plus the excesses you actually pay on claims.
• Licensing and permits — licence disc, operating licences, cross-border permits, roadworthy testing.
• Tracking and software — telematics subscription, fleet software, fuel cards.
• Overheads you allocate — yard, fleet admin staff, if you want a fully loaded figure.

Semi-fixed costs

• Driver cost — salary, overtime, benefits, subsistence, training. Mostly time-based, partly trip-based. Report CPK with and without driver cost: the first for pricing, the second for comparing vehicles.

Variable costs (distance-based)

• Fuel — litres used × price paid. If you draw from your own bulk tank, value it at weighted-average cost rather than the last pump price.
• Tyres — purchase, fitment, repairs and retreads, spread over the kilometres each tyre actually lasts.
• Maintenance and repairs — services, parts, workshop labour (internal and external), breakdown call-outs.
• Tolls.
• Traffic fines you could not recover from the driver.
• Incidents — repair costs not covered by insurance and the revenue lost while the vehicle is off the road.

3. Worked example: an 8-ton delivery truck

The numbers below are illustrative — substitute your own. The truck runs 90,000 km a year at an average of 25 litres per 100 km.

Notice that the fuel line depends on two numbers you should capture per fill, not per month: litres and price. If your drivers fill at different sites, or you draw from your own bulk tank, the cost per litre varies — so record each fill against the vehicle and its odometer reading. That same data gives you consumption in litres per 100 km, which is the first place to look when a vehicle’s CPK moves.

Two things stand out. Fuel is the biggest single line, but it is only about 41% of the total. And more than half of every rand — depreciation, finance, insurance and the driver — is spent whether the truck moves or not.

4. Why kilometres matter as much as costs

Now suppose the same truck only runs 70,000 km next year because it sat for weeks waiting for a part and lost a route. Fixed and driver costs barely change (R590,000), and variable costs fall with distance:

That is 14% more per kilometre for the same vehicle, with no change in fuel price. If your rates were set on R13.33, that route is now losing money. This is why downtime and utilisation belong in every CPK review: a vehicle that is cheap to run but often off the road is not a cheap vehicle.

5. From cost per km to lifetime TCO

Total cost of ownership is the same idea measured over a vehicle’s whole life:

TCO is how you compare a cheaper truck with a dearer, more fuel-efficient one, or buying against leasing. Track it per vehicle and watch the trend. Maintenance cost per km usually creeps up with age; when the rising maintenance and downtime line crosses the falling depreciation line, you have reached the economic replacement point. A six-month cost trend per vehicle shows that crossover early, while you still have time to budget for the replacement.

6. Six mistakes that distort cost per km

1. Counting only fuel and maintenance. Leaving out depreciation, finance and insurance can understate CPK by a third or more.
2. Using budgeted rather than actual kilometres. Use odometer readings, and protect them against rollback or mis-keyed readings.
3. Fleet averages instead of per-vehicle figures. An average hides the two trucks that cost twice as much as the rest.
4. Valuing bulk fuel at the wrong price. If you buy diesel into your own tank at different prices, use weighted-average cost — otherwise CPK swings with whichever delivery came last.
5. Ignoring tyres as an asset. Tyres are expensive rotables. Track them per position and serial number, so you know cost per km per tyre and catch the ones that fail early.
6. Forgetting incidents, fines and tolls. They sit in different budgets, but they are vehicle costs.

7. How to use cost per km to make decisions

• Pricing: quote routes and contracts on fully loaded CPK plus margin, adjusted for empty return legs.
• Vehicle comparison: rank vehicles on CPK excluding driver, by vehicle type, and investigate the outliers.
• Replacement: replace on rising TCO trend and downtime, not on age alone.
• Driver coaching: compare fuel consumption (L/100 km) by driver on similar routes.
• Make-or-buy: compare your CPK with subcontractor rates for each lane.

If you run under RTMS, productivity measures like CPK and downtime also give your auditor evidence that your system is managed — see our RTMS compliance checklist.

How SynchPlus ONE helps

The hard part of CPK is not the arithmetic — it is getting every cost onto the right vehicle without a spreadsheet. The SynchPlus ONE fleet management module does that on one record:

• Automatic per-vehicle TCO: fuel, maintenance, labour, insurance, depreciation, tolls and fines rolled into lifetime cost and cost-per-km.
• Fuel management from pump, bulk tank or external suppliers, with weighted-average cost pricing and L/100 km and km/L analytics.
• Tyres and rotables tracked per position by brand, serial and tread, with service life in kilometres.
• Odometer history that is linked to fuel and protected against rollback.
• Incidents and claims linked to the vehicle, plus a six-month cost trend, forecast, replacement scores and downtime revenue-loss.

Because inventory, dispatch and the workshop live on the same platform, the parts, trips and labour flow into CPK without re-keying. SynchPlus ONE runs in any country — on your servers or our cloud. If you run collections, deliveries or hire fleets, see last-mile delivery and plant hire software, or check pricing.

Frequently asked questions