Accumulated Depreciation

Contra-asset balance showing the total depreciation recorded against a depreciable asset since acquisition.

Definition

Accumulated depreciation is the contra-asset balance that shows the total depreciation recorded against a depreciable asset since it was placed in service. It reduces the asset’s carrying amount on the balance sheet without erasing the original historical cost.

Why It Matters

Readers use accumulated depreciation to see how much of an asset’s cost has already been allocated to expense. It helps explain book value and carrying amount, supports replacement planning, and shows whether fixed-asset balances are mostly new or already heavily depreciated.

How It Works In Accounting Practice

Each depreciation entry usually credits accumulated depreciation rather than the asset account directly. That preserves two useful numbers at once: original cost and total depreciation to date.

When the asset is sold, retired, or written off, both the asset cost and its accumulated depreciation are removed from the accounts before any gain or loss is recognized.

Simple Example

Equipment cost is 24,000 and accumulated depreciation after three years is 6,000:

Line ItemAmount
Equipment cost24,000
Less accumulated depreciation(6,000)
Net book value18,000

The 6,000 balance is not a separate liability. It is the running total of depreciation already recognized.

Common Confusions

Accumulated depreciation is not the same as current-period depreciation expense. Expense is the amount for one period. Accumulated depreciation is the total built up across many periods.