How to Calculate Shift Depreciation (Double & Triple Shift) Correctly
Why manufacturers routinely get double- and triple-shift depreciation wrong in Excel, and how Schedule II Part C actually applies the extra depreciation.
Assets worked on extra shifts wear out faster, and Schedule II Part C requires extra depreciation for the period they run double or triple shift. The rule is proportional — and that proportionality is exactly what hand-built spreadsheets tend to get wrong.
The uplift, and how it scales
- Double shift: depreciation is increased by 50% for the portion of the year the asset ran double shift.
- Triple shift: depreciation is increased by 100% for the portion of the year the asset ran triple shift.
- The uplift is scaled by shift-days ÷ days in the financial year — not applied to the whole year unless the asset ran that shift all year.
The exclusions people miss
No-Extra-Shift-Depreciation (NESD) assets, intangibles and land never attract shift uplift. Applying a blanket 1.5x or 2x factor across a plant — the usual Excel shortcut — over-depreciates these and understates profit.
AssetOS applies Part C shift depreciation by rule — scaled by the days each asset actually ran each shift, with exclusions handled — so plants stop reconciling shift factors by hand.