How to Calculate Cost Inflation Index (CII) for Capital Gains Tax in India
Understanding the Cost Inflation Index (CII) in Real Estate
Selling a property in India often attracts Long-Term Capital Gains (LTCG) tax if you have held the asset for more than 24 months. However, the Indian Income Tax Department allows a massive tax relief benefit called indexation. This benefit adjusts the purchase price of your property upward to account for inflation over the years, drastically reducing your taxable gains.
The key metric used to calculate this inflation adjustment is the Cost Inflation Index (CII), which is declared annually by the Central Board of Direct Taxes (CBDT).
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How is the Indexed Cost of Acquisition Calculated?
To find out how much your property purchase price has inflated over time, use the following official Income Tax formula:
Indexed Cost = Purchase Price × (CII of Sale Year / CII of Purchase Year)
Example Calculation
Suppose you purchased a residential apartment in Hyderabad in the Financial Year 2015-16 (CII = 254) for ₹40 Lakhs and sold it in the Financial Year 2024-25 (CII = 363) for ₹80 Lakhs:
- CII of Purchase Year (2015-16): 254
- CII of Sale Year (2024-25): 363
- Indexed Cost of Acquisition: ₹40,000,000 × (363 / 254) = ₹57,16,535
- Net Capital Gain: ₹80,00,000 - ₹57,16,535 = ₹22,83,465 (instead of the raw ₹40 Lakhs gain!)
By using indexation, your taxable capital gains dropped from ₹40 Lakhs to just ₹22.8 Lakhs, saving you lakhs of rupees in tax payouts.
Recent Budget Changes: The 12.5% Tax Rate Options
In the latest budget updates, the government introduced a flat 12.5% LTCG tax rate (without indexation) alongside the traditional 20% LTCG tax rate (with indexation) for properties acquired before July 2024. Homeowners now have the unique flexibility to choose whichever option results in a lower tax obligation. Our tools dynamically calculate both routes to help you make the best choice.