How do you calculate a machine's cost per hour?

1. Two costs: owning it and running it

The owning and operating cost method, the one Komatsu publishes in its specifications and application handbook, works for any machine of any brand. The owning cost is paid even when the machine is parked; the operating cost only runs when it works. That's why utilisation matters so much: a machine that works half the planned hours carries twice the owning cost in every hour.

2. Depreciation: what you lose, not what you pay

What depreciates is the delivered price minus resale value, spread over the hours you'll work it. Illustrative example, with a hypothetical tracked machine: it costs US$ 100,000, works 2,000 hours a year and resells for US$ 25,000 after four years. It depreciates US$ 75,000 over 8,000 hours: US$ 9.38 per hour. On wheeled equipment, the tyres' value is deducted from the price before depreciating and counted separately, because they wear out long before the machine. Resale is the input that moves this number most, and the one almost nobody asks about when buying.

3. Interest, insurance and taxes

The money put into the machine pays interest if borrowed and stops earning if it's your own; it's also insured and taxed. Since its value falls each year, it's calculated on the average investment, with a factor that depends on the years (n) and the resale ratio (r): factor = 1 − (n − 1) × (1 − r) ÷ 2n. With four years and 25 % resale the factor is 0.719. If interest, insurance and taxes add up, in the example, to 15 % a year: US$ 100,000 × 0.719 × 0.15 ÷ 2,000 hours = US$ 5.39 per hour. With depreciation, owning comes to US$ 14.77.

4. Fuel: measure it, don't assume it

Hourly consumption times the local price of diesel. Consumption isn't fixed by the model: manufacturers publish it for light, medium and heavy conditions, and the gap between them is large. In the example, 12.5 litres per hour with diesel at US$ 1.10 is US$ 13.75 per hour. The exact figure comes from measuring it in your operation: on Komatsu, KOMTRAX — included at no cost, per Komatsu — logs real fuel use per hour and idle hours.

Part of consumption depends on how the machine is run and maintained. According to Komatsu's fuel-saving guide, one hour of idling a day on a 20 t excavator is about 990 litres a year, and a dirty air filter raises consumption by about 3 %.

5. Lubricants, filters, tyres, repairs and operator

Lubricants: litres per change divided by the interval, times the local price. Filters: their price over their interval; as a quick estimate, about half of what lubricants cost, and more in dusty ground. Tyres: the price of the set over its life in hours, which varies enormously with the surface. Repairs: they start low and rise with the hours, so they're averaged over the whole life; it's the hardest item to estimate without history, which is why you ask the dealer, who has the model's data in similar applications. Fast-wear parts — tips, cutting edges — go separately. And the operator, at their real cost per hour.

6. The full example, and why the cheaper machine can cost more

With the illustrative assumptions above: owning US$ 14.77; operating US$ 22.44 (fuel US$ 13.75, lubricants and filters US$ 0.39, repairs US$ 3.30 and operator US$ 5.00). Total: US$ 37.21 per hour. Depreciation — the only thing the purchase price moves directly — is barely a quarter; fuel weighs more.

Now a hypothetical machine 10 % cheaper, US$ 90,000, that resells for 15 % instead of 25 % and burns 15 % more. Its depreciation rises to US$ 9.56, it saves a little interest, and fuel goes to US$ 15.81: total US$ 38.66 per hour. Over 8,000 hours, the one that cost US$ 10,000 less ends up over US$ 11,000 more expensive. It's not a brand argument, it's arithmetic that changes with your numbers. Before comparing stickers, ask what it resells for and how much it burns in an application like yours.

7. From cost per hour to cost per tonne

Cost per hour doesn't tell you whether the machine is profitable: you need what it produces. Dividing it by hourly output gives cost per cubic metre or per tonne, which is what a job is priced with. A US$ 40-per-hour machine that moves 200 tonnes costs US$ 0.20 per tonne; a US$ 35 one that moves 140 costs US$ 0.25. The more expensive per hour is the cheaper per tonne. In a fleet it gets harder, because each machine depends on the others: one truck too many queues, one too few leaves the excavator waiting. That's what a fleet study solves.

8. The calculator and the fleet study

For a first figure, the cost-per-hour calculator at /calculadoras asks for purchase price, service life in hours, operating hours per month, fuel per hour and maintenance plus parts per hour, and gives you depreciation, fuel and maintenance per hour and the monthly cost. It's a quick version: it doesn't deduct resale or add interest, insurance or operator, so complete it with this guide's method.

If you run a quarry, a mine or a large earthmoving job, the fleet study (/estudio-de-flota) compares alternatives with your material, your haul routes and your costs, and gives you the cost per tonne of each. Grupo ConstruMarket serves you from branches in El Salvador (Zaragoza, Antiguo Cuscatlán, San Miguel), Guatemala (Mixco, Río Hondo, Xela), Nicaragua (Managua) and Panama (Panama City).