Fleet Cost per Kilometer Explained

Two trucks can drive the same route and cost completely different amounts to run. Cost per kilometer is the number that exposes that difference — and without it, pricing a route or comparing vehicles is guesswork.

The formula

Cost per KM = (Fixed Costs + Variable Costs) ÷ Total KM Driven

The formula looks simple, but it only works if fixed and variable costs are both captured correctly — and kept separate in your thinking, even though they combine into one final number.

Fixed vs variable costs

Fixed costs are incurred whether the truck drives 10km or 10,000km this month: insurance, licensing, depreciation. Variable costs scale directly with distance: fuel, tyres, routine maintenance, driver allowances tied to trips.

Splitting the two matters because they respond differently to decisions — adding a route mostly adds variable cost, while an idle truck still burns fixed cost even parked.

Worked example

A delivery truck drives 4,000km in a month:

• Fixed costs (insurance, licensing, depreciation, base salary): USD 620
• Variable costs (fuel, tyres, maintenance, trip allowances): USD 980

Cost per KM = (620 + 980) ÷ 4,000 = USD 0.40 / km

That per-km figure is what any route or delivery priced below effectively loses money on — and it's easy to lose sight of when pricing is set per delivery rather than per kilometer driven.

Allocating depreciation correctly

Take the vehicle's purchase price minus its expected resale value, divide by its useful life in years to get annual depreciation, then divide by expected annual kilometers. This gives a defensible per-km depreciation rate instead of guessing — and it should sit in the fixed-cost side of the formula, not variable.

Where driver cost belongs

Base salary is fixed — it's paid whether the truck moves or not. Overtime, per-diem and trip allowances are variable — they scale with trips and distance. Splitting driver cost this way, rather than treating it as one lump figure, is one of the most common places fleet costing goes wrong.

Using cost per km for pricing and route decisions

Once cost per km is known per vehicle — not just fleet-wide — three decisions get much easier:

• Pricing: any rate quoted below cost per km times distance is a loss-making trip, even if it "feels" profitable on paper.
• Route comparison: a route with more stops but shorter distance can cost more per km than a longer, simpler route — visible only once cost per km is tracked, not assumed.
• Fleet renewal: a vehicle whose cost per km is climbing season over season, independent of fuel price changes, is signalling rising maintenance cost — a data-backed case for replacement.

Why cost per km varies between vehicles in the same fleet

Age, route terrain, load weight and maintenance history all affect fuel burn and wear differently per vehicle. Tracking cost per km per vehicle — not just as a single fleet average — is usually what reveals which trucks are quietly dragging down overall margin.

Summary

Cost per km = (fixed + variable costs) ÷ total km driven. Keep fixed and variable costs separate in your tracking even though they combine in the final number, allocate depreciation and driver cost correctly, and track the metric per vehicle — not just fleet-wide — to see where the real cost is coming from.