What Is Depreciation? Methods, Calculation, and How It Flows Through Financial Statements

What Is Depreciation?

Picture a delivery truck. On the day you buy it, it's worth ₹28 lakh. Five years later, even if it has never been in an accident, it's worth a fraction of that — maybe ₹9 lakh. The truck has been used to generate revenue every month, and with every kilometre driven, some of that original value has been consumed. Depreciation is the accounting mechanism that records this gradual consumption.

The key word is systematic. Depreciation isn't based on what an asset is actually worth on any given day — that's a market valuation question. Instead, it's a scheduled, rule-based process that spreads the cost of an asset across the periods that benefit from its use. It follows the matching principle in accounting: expenses are recognised in the same period as the revenues they help generate.

Depreciation applies only to tangible fixed assets — things like machinery, vehicles, computers, furniture, and buildings. It does not apply to land (land doesn't wear out), to current assets like inventory (those are expensed differently), or to financial assets like shares and bonds. The equivalent concept for intangible assets — patents, trademarks, software licences — is called amortisation, which works the same way but has a different name.

Why Depreciation Exists

Depreciation exists because of a fundamental problem with asset accounting: the cost of a long-lived asset doesn't match the period in which you pay for it.

Suppose a factory buys a cutting machine for ₹60 lakh. Without depreciation, the entire ₹60 lakh would hit the income statement as an expense in Year 1 — the year of purchase — making profit look terrible that year and artificially high in every subsequent year the machine continues to operate. That's a distorted picture of the business's true performance.

Depreciation solves this by spreading the ₹60 lakh over the machine's 10-year useful life: ₹6 lakh per year. Now the income statement shows a consistent ₹6 lakh cost each year — directly tied to the year the machine was actually being used. The profit figure in each year is a more accurate reflection of how much value the business created.

"Depreciation doesn't represent cash leaving your bank account — it represents value that was already spent, being recognised at the right time."

This is why depreciation is called a non-cash charge. The cash was paid when the asset was purchased. The depreciation charge on the income statement is simply the accountant's way of saying: "This much of the asset's value was consumed this year." No cash moves when depreciation is recorded. This distinction matters enormously when you move from net income to operating cash flow — a topic we'll return to later.

There are three inputs you need before calculating any depreciation figure:

• Cost of the asset — the purchase price plus any costs to get it ready for use (installation, delivery, testing)
• Salvage value (residual value) — the estimated amount you expect to receive when you eventually sell or scrap the asset
• Useful life — how many years (or hours, or units) the asset is expected to remain in productive use

The difference between cost and salvage value is the depreciable base — the amount that gets spread over the asset's life. For a machine costing ₹9,40,000 with an estimated salvage value of ₹40,000, the depreciable base is ₹9,00,000.

The Four Depreciation Methods

Different assets lose value at different rates. A brand-new laptop becomes obsolete faster in its first year than its fifth. A warehouse floor wears down at roughly the same rate each year. Accounting standards (GAAP and IFRS both permit this) allow companies to choose the method that best reflects how an asset actually loses value — as long as the method is applied consistently.

To compare all four methods side by side, we'll use one consistent example throughout:

Straight-Line Method (SLM)

The simplest and most widely used method. You divide the depreciable base equally across every year of the asset's useful life. The annual charge is constant — it never changes from year to year, which makes planning and reporting straightforward.

Straight-line is preferred when an asset is expected to provide roughly equal economic benefit in each period — buildings, office furniture, and long-lived factory equipment are good candidates. It's also favoured for external reporting because it's predictable and easy to audit.

Declining Balance Method (DBM)

The declining balance method applies a fixed percentage rate to the asset's book value at the start of each year, rather than to the original depreciable base. Because book value falls as depreciation accumulates, the expense is higher in early years and gradually decreases. This is called an accelerated depreciation method.

The declining balance method makes intuitive sense for technology assets. A computer or a smartphone loses a disproportionate share of its value in the first year — the moment it leaves the shop. Matching a larger depreciation charge to those earlier, higher-value years reflects economic reality more accurately for such assets.

Units of Production Method

This method ties depreciation directly to usage. Rather than running on a calendar, it runs on a usage meter — the asset depreciates by a fixed amount per unit produced, per hour operated, or per kilometre driven. In years of heavy use, the charge is high. In slow years, it's low.

Units of production is common in manufacturing (machine hours), mining (tonnes extracted), and transportation (kilometres driven). It's rarely used for general purpose assets like buildings or office equipment, where usage is difficult to measure meaningfully.

Sum-of-the-Years'-Digits Method (SYD)

Sum-of-the-years'-digits is a second accelerated method. It applies a declining fraction to the depreciable base (not the book value), where the fraction numerator is the remaining useful life and the denominator is the sum of all the year numbers in the asset's life.

How Depreciation Flows Through the Financial Statements

Depreciation is unusual in that it leaves a mark on all three core financial statements — each one differently. Understanding this is essential for reading annual reports with any confidence.

Income Statement: Reduces Operating Profit

Depreciation expense appears as an operating cost on the income statement. It reduces EBIT (Earnings Before Interest and Tax), and therefore reduces net profit. A company with significant fixed assets will have higher depreciation charges, which lowers reported earnings — even if no cash is leaving the business in that period.

Notice that depreciation reduced net profit by ₹84,375 — not the full ₹1,12,500 — because it also reduced taxable income, generating a tax saving of ₹28,125. This is called the tax shield effect of depreciation, and it's one reason companies sometimes prefer accelerated methods: higher depreciation early → lower taxable income → tax is deferred to later years.

Balance Sheet: Reduces Net Book Value

On the balance sheet, a fixed asset is shown at its original cost minus the total accumulated depreciation to date. This net figure is called net book value (NBV) or carrying value.

The gross cost stays at ₹9,40,000 until the asset is disposed of. What changes each year is the accumulated depreciation figure — it grows by one year's depreciation expense, reducing the net book value. This is also why balance sheets show two numbers for fixed assets in the notes: the original cost and the accumulated depreciation.

Cash Flow Statement: Added Back to Operating Profit

This is where depreciation's non-cash nature becomes operationally important. In the indirect method of preparing the cash flow statement, you start with net profit and adjust it to arrive at operating cash flow. Since depreciation was deducted to calculate net profit but no cash actually left the business, it must be added back.

This is why EBITDA — Earnings Before Interest, Taxes, Depreciation and Amortisation — is such a popular metric for analysts. By adding back D&A, EBITDA approximates the operating cash earnings of the business before financing choices and accounting conventions distort the picture. A capital-intensive business (lots of factories and machines) will have a large gap between net profit and EBITDA; a software company with few physical assets will have a small gap.

Accumulated Depreciation vs. Depreciation Expense

These two terms sound similar but they record very different things, and confusing them is one of the most common mistakes beginners make when reading financial statements.

Accumulated depreciation is a contra-asset account — it carries a credit balance that reduces the asset's gross carrying value to its net book value. When you eventually sell or scrap the asset, both the gross cost and the accumulated depreciation are removed from the balance sheet. Any difference between proceeds received and net book value is recorded as a gain or loss on disposal.

Tax Depreciation vs. Book Depreciation

Here is where things get practically important for analysts and finance teams alike. Companies maintain two separate depreciation schedules — one for financial reporting (book depreciation) and one for tax purposes (tax depreciation). They rarely match, and the difference creates a deferred tax liability on the balance sheet.

Book depreciation follows accounting standards (GAAP or IFRS) and is chosen to most accurately represent the consumption of the asset's economic value. Straight-line is the most common choice for financial reporting.

Tax depreciation follows the rules set by the tax authority (for example, India's Income Tax Act allows Written Down Value depreciation at prescribed rates for different asset classes). Tax depreciation is almost always accelerated — higher charges in early years — because companies want to reduce taxable income now and defer tax payments to the future.

This timing difference is why deferred tax liabilities are so common on the balance sheets of capital-intensive companies. It's not tax avoidance — it's tax deferral. The full tax is eventually paid; it's just shifted to later periods.

Common Misconceptions About Depreciation

A few ideas about depreciation are widespread but wrong. Getting these straight is what separates someone who has read about accounting from someone who actually understands it.

Misconception 1: Depreciation represents cash set aside for replacement

This is the most persistent myth. Depreciation does not mean a company is saving money to replace an asset. The depreciation charge is purely an accounting entry — it reduces reported profit and reduces the asset's book value, but it does not move cash into a reserve fund. If a company wants to fund asset replacement, it needs to plan capital expenditure separately. The two are independent.

Misconception 2: Net book value = market value

Net book value is what the asset cost, minus what's been charged off under an accounting method. It says almost nothing about what the asset would actually sell for today. A five-year-old machine might have a book value of ₹3 lakh (original cost ₹9,40,000 minus five years of straight-line depreciation) but sell on the secondary market for ₹7 lakh — or ₹50,000. Market value and book value diverge constantly, especially for real estate. The balance sheet reflects cost history, not market reality.

Misconception 3: Companies can change depreciation methods freely to manage earnings

Accounting standards require consistency: once a method is chosen for a class of assets, it should be applied consistently year after year. Changing methods is permitted only when the new method results in more relevant or reliable information, and any change must be disclosed prominently in the financial statements, including the effect on profit. Auditors and analysts watch for unexplained method changes because they can be a red flag for earnings management.