Truck Depreciation Calculator

Fastest at the start: roughly 20–30% in year one for a new tractor, and around half of original value by year three or four — then flattening, because a sound running truck always retains drivetrain value. Drivers of the curve: odometer miles (the dominant factor), maintenance documentation, idle-hour ratio on the ECM, engine/emissions generation, configuration (sleeper, gearing) and the used-truck market cycle, which swings hard with freight demand. A five-year-old truck with 550k documented miles holds value dramatically better than the same truck with 750k and no records.

Yes. A paid-off truck still consumes value with every mile — that value is real money you'll realize (or not) at trade time, and the truck's replacement must eventually be funded. Operators who drop depreciation from CPM after payoff systematically underprice, then face a replacement purchase with no reserve. The cleaner mental model: the payment was financing; depreciation is the asset being used up. Keep 8–12 cents/mile (or this calculator's output) in your cost basis and bank it as a replacement fund — your future self buys the next truck in cash.

Economic depreciation is value actually consumed — purchase price minus realistic resale, spread over the holding period; it belongs in pricing and planning. Tax depreciation is an IRS deduction schedule: tractors are 3-year MACRS property (trailers 5-year), and Section 179 plus bonus depreciation can allow expensing most of the cost very early. They serve different purposes: tax depreciation accelerates deductions for cash-flow benefit but doesn't change what the truck really costs per mile — and writing a truck down to zero then selling it triggers depreciation recapture (ordinary income) on the sale proceeds. Plan with economic; file with tax rules.

Look at the actual used market for your truck's age-plus-holding-period and projected mileage: auction results, dealer listings and trade-in offers for comparable spec (engine, transmission, sleeper, miles) give a live range. Then haircut for honesty — used-truck prices are cyclical and you can't time your exit; estimating salvage at the optimistic top of a hot market is how depreciation gets understated. Maintenance records, a clean ECM (modest idle), rust-free chassis and desirable spec all add realizable value. Re-estimate annually: the salvage input is the one that moves, and your per-mile depreciation should move with it.