Full cost-accounting machine rate (Maschinenstundensatz) for estimators and controllers: linear depreciation to residual value, imputed interest on average capital, floor-space, energy with duty factor, maintenance, tooling — diluted over real annual operating hours — plus operator labor and overhead surcharge to the total hourly rate and cost per part. Utilization sensitivity shows exactly how idle hours destroy the rate. Every report with the full audit trail — quote prices you can defend.
The machine-hour rate splits into a fixed block (incurred whether the spindle turns or not) and a variable block (incurred per running hour):
Imputed interest uses the average capital employed (price + residual)/2 — the money tied up in the machine has an opportunity cost whether or not a bank financed it. Depreciation is linear to residual, the standard management-accounting convention; tax depreciation differs deliberately and belongs in the tax books, not the quote.
Every fixed euro is diluted by the operating hours. At 1 500 h/yr the fixed block of the default example costs ≈ 35 €/h; at 4 500 h/yr the same block costs ≈ 12 €/h — a 23 €/h swing on the quote from a scheduling decision, not an engineering one. This is why the sensitivity chart matters more than any single line item: the cheapest machine is a busy one. Use real spindle-on / arc-on hours, not shift attendance — presence time overstates utilization by 30–50 % on typical shops and prices work you then cannot deliver at margin.
Using purchase price only: tooling, installation, foundation and commissioning are 10–25 % on top and belong in the capital base. Forgetting imputed interest: financed or not, capital is never free. Nominal instead of duty-factored power: a 15 kW nameplate rarely draws 15 kW continuously; 50–70 % duty is typical for machining. Zero maintenance budgeting: 4–8 % of replacement value per year is the honest band for CNC equipment. Charging shift hours: see above — the single most expensive lie in job costing.
€250 k machining center, €25 k residual, 10 yr, 3 500 h/yr, 6 % interest, 40 m² at €120, 15 kW at 60 % duty and €0.18/kWh, 5 % maintenance, €4 k tooling, €1.5 k other: fixed ≈ €54 050/yr → €15.4/h + energy €1.6/h → machine €17.1/h. Labor €38/h shared over 2 machines → €19/h. With 20 % overhead the total rate ≈ €43.3/h. A 90 s cycle then costs ≈ €1.08 of machine time — the number that decides whether the quote wins and pays.
Why is my shop rate higher than a competitor's with the same machine? Usually utilization and space, not the machine. Compare operating hours first, then space allocation, then maintenance budgeting — the capital block is rarely the differentiator.
Should I use replacement value or purchase price? For pricing, replacement value is the defensible modern practice (you must re-buy at tomorrow's price); for book accounting, historical price. The engine takes either — document the choice in the audit trail.
How do I cost a machine shared across product lines? Allocate by real hours consumed per line and keep one audited rate per machine — blended shop-wide rates hide winners and losers in the same average.
What overhead percentage is honest? Whatever your controller can trace: admin, quality, logistics, IT. 15–30 % on machine+labor is typical for job shops; the audit trail makes the choice visible instead of hiding it in a margin guess.
