Depreciation Calculator (SLM and WDV, Income Tax Rates)

Straight-line (SLM) spreads cost minus salvage value evenly over the useful life, so the charge is the same every year and the book value falls in a straight line to the salvage value.

Written-down value (WDV) charges a fixed percentage of the value left at the start of each year, so the charge is largest in the first year and keeps shrinking. It never quite reaches zero; the calculator stops it at the salvage value you enter.

For income tax, depreciation on a block of assets is a percentage of written-down value set in Appendix I to the Income-tax Rules, 2026: for example 15% for general machinery and plant and 40% for computers and software. Pick a block to fill in its rate. Under income tax an asset put to use for less than 180 days in the year it is bought gets half the rate that year.

If you choose a half or part first year under SLM, the part not charged in year one is charged in an extra year at the end, so the asset still reaches its salvage value. The useful life for SLM is your entry; the calculator does not supply company-law useful lives.

Worked examples: a ₹1,00,000 computer under the income-tax 40% WDV rate is depreciated by ₹40,000 in year 1, ₹24,000 in year 2 and ₹14,400 in year 3, if used for 180 days or more in the first year; bought later in the year, year 1 gets half, ₹20,000. A ₹10,00,000 machine with a ₹1,00,000 salvage value over 10 years by straight line is ₹90,000 a year.

Car depreciation: a ₹10,00,000 car used for business is depreciated at 15% WDV for income tax: ₹1,50,000 in year 1, ₹1,27,500 in year 2 and ₹1,08,375 in year 3, leaving a book value of ₹6,14,125. That is a tax figure, not the car's resale price; for insurance, the insured declared value (IDV) uses the age-based table below.

For company accounts, the Companies Act, 2013 (Schedule II) sets useful lives instead of rates, for example 3 years for laptops and desktops, 8 years for motor cars, 10 years for furniture, 15 years for general plant and machinery and 60 years for non-factory RCC buildings; enter the life here and use straight line. Business owners can see the tax effect with the Self-Employed Tax Calculator.

Car and bike depreciation for insurance (IDV)

Insurers use this schedule to set the insured declared value (IDV), the most a claim pays for a total loss or theft. It is not the income-tax rate, and resale prices vary with model and condition.