Calculate Indexed Cost of Acquisition (ICOA), Indexed Cost of Improvement (ICOI), and Long-Term Capital Gains (LTCG) tax using the official CBDT Cost Inflation Index (CII 2001-02 to 2025-26) with Budget 2024 real estate grandfathering comparator.
Original cost ₹ 10.00 Lakh inflated from FY 2001-02 (CII: 100) to FY 2024-25 (CII: 363).
| Financial Year (FY) | Assessment Year (AY) | Cost Inflation Index (CII) | YoY Inflation Rise (%) | Cumulative Inflation from Base |
|---|
The Cost Inflation Index (CII) is a statutory financial index notified annually by the Central Board of Direct Taxes (CBDT) under Section 48 of the Income Tax Act, 1961. Its primary economic purpose is to neutralize the distorting effect of inflation on long-term capital investments.
When an investor purchases a capital asset—such as a residential home, commercial plot, agricultural land, gold, or unlisted shares—and sells it several years later, the nominal selling price is inevitably higher due to ongoing macroeconomic inflation. If tax were levied on the raw difference between the sale price and the original purchase price, the taxpayer would be unfairly penalized for inflation rather than real wealth creation.
By applying the Indexed Cost of Acquisition (ICOA) formula, the original purchase price is scaled upward to reflect the current purchasing power of money, substantially shrinking the taxable capital gains and resulting in massive legitimate tax savings.
The Income Tax Act prescribes the exact mathematical formulas for indexing purchase costs and renovation expenditures:
Consider an investor who purchased a residential apartment in FY 2004-05 for ₹20,00,000 and sold it in FY 2024-25 for ₹80,00,000:
The Union Budget presented on July 23, 2024, initially removed indexation benefits across all asset classes and lowered the LTCG tax rate from 20% to 12.5%. However, to protect millions of middle-class property owners whose assets had appreciated slowly over decades, the Ministry of Finance enacted a crucial grandfathering amendment in the Finance (No. 2) Act, 2024:
The Dual-Option Rule for Immovable Property: For any land or building purchased by a resident Indian individual or HUF prior to July 23, 2024, the seller has the legal right to compute capital gains tax under both methods:
The taxpayer is legally permitted to select whichever option results in the lower tax payout. Our calculator automatically computes both methods side-by-side and recommends the most profitable option.
In FY 2017-18, the Central Government shifted the base year of the Cost Inflation Index from 1981-82 to 2001-02. For capital assets acquired before April 1, 2001, specific statutory valuation rules apply under Section 55 of the Income Tax Act:
Even after calculating long-term capital gains using the Cost Inflation Index, taxpayers can achieve 100% tax exemption by reinvesting their gains into designated tax-saving instruments:
| Section | Eligible Asset Sold | Reinvestment Destination | Timeline & Maximum Limit |
|---|---|---|---|
| Section 54 | Residential House Property | Purchase / Construct a new residential house in India | Buy 1 yr before / 2 yrs after, or construct within 3 yrs (Max ₹10 Crore). |
| Section 54EC | Land, Building, or Real Estate | Specified Capital Gains Bonds (REC, PFC, NHAI, IRFC) | Invest within 6 months of sale. Max ₹50 Lakh per FY (5-year lock-in). |
| Section 54F | Any asset other than house (Gold, Land, Shares) | Purchase / Construct a residential house property | Must reinvest entire net sale proceeds (not just the gain). Max ₹10 Crore. |
The applicability of the Cost Inflation Index varies significantly depending on the nature of the capital asset:
The Cost Inflation Index is not an arbitrary figure; it is mathematically linked to the Consumer Price Index for Urban Non-Manual Employees (CPI-UNME) and the national Consumer Price Index (CPI-Combined) published by the Ministry of Statistics and Programme Implementation (MoSPI).
Each year, before the commencement of the new Assessment Year, the CBDT assesses average retail price inflation across essential commodities, housing, healthcare, and services over the preceding 12 months and issues a gazette notification establishing the new index number.
If an investor sells property and intends to claim exemption under Section 54 or Section 54F by buying or constructing a new house, but the statutory due date for filing their Income Tax Return (July 31 / October 31) arrives before the purchase is completed, they must deposit the unutilized capital gains into a Capital Gains Account Scheme (CGAS) with an authorized public or private bank.
Depositing the funds in a CGAS Type A (Savings) or Type B (Term Deposit) account before the ITR filing deadline ensures that the taxpayer can claim full Section 54/54F exemption in their return while utilizing the funds within the permissible 2 to 3-year window.
The Cost Inflation Index (CII) is a statutory measure notified annually by the Central Board of Direct Taxes (CBDT) under clause (v) of the Explanation to Section 48 of the Income Tax Act, 1961. It is used to calculate the Indexed Cost of Acquisition (ICOA) and Indexed Cost of Improvement (ICOI) when computing Long-Term Capital Gains (LTCG) on the transfer of capital assets (such as real estate, gold, and unlisted shares). By adjusting the original purchase price for inflation over the holding period, CII ensures taxpayers only pay capital gains tax on real economic profits rather than artificial, inflation-driven price increases.
The CBDT officially notified the Cost Inflation Index for the Financial Year 2024-25 (Assessment Year 2025-26) as 363 via Notification No. 44/2024 dated May 24, 2024. For the Financial Year 2025-26 (Assessment Year 2026-27), the projected/applicable CII is 377. The base year for the current index series is 2001-02 with a base value of 100.
The Indexed Cost of Acquisition is calculated using the statutory formula: Indexed Cost of Acquisition (ICOA) = Purchase Price (or Fair Market Value as on April 1, 2001 for pre-2001 assets) × (CII of the Year of Sale / CII of the Year of Purchase or FY 2001-02, whichever is later). Similarly, Indexed Cost of Improvement (ICOI) = Cost of Improvement × (CII of the Year of Sale / CII of the Year of Improvement).
Under the Finance (No. 2) Act 2024, the government rationalized LTCG tax on immovable property to 12.5% without indexation for sales on or after July 23, 2024. However, in response to public representations, the government introduced a historic grandfathering amendment: For properties (land or building) acquired by resident individuals or HUFs prior to July 23, 2024, taxpayers are given the option to compute their LTCG tax under either: (1) 12.5% without indexation, OR (2) 20% with indexation, and pay whichever tax liability is lower. This protects legacy property owners from higher tax burdens where asset appreciation was primarily driven by inflation.
For capital assets acquired before April 1, 2001, Section 55 of the Income Tax Act allows the taxpayer to substitute the actual purchase cost with the Fair Market Value (FMV) of the asset as on April 1, 2001 (provided that for immovable property, the FMV does not exceed the stamp duty value as on April 1, 2001). The base year CII of 100 (for FY 2001-02) is then applied to this April 1, 2001 valuation to compute the indexed cost of acquisition.
Indexation applicability varies across asset classes: (1) Listed Equity Shares & Equity Mutual Funds: Indexation is not available; LTCG is taxed at a flat 12.5% (post-Budget 2024) on gains exceeding ₹1.25 Lakh per year under Section 112A. (2) Debt Mutual Funds acquired on or after April 1, 2023: Indexation is completely removed under Section 50AA; gains are taxed at slab rates as short-term capital gains. (3) Physical Gold, Jewelry & Unlisted Shares: LTCG is taxed at 12.5% without indexation (post-July 23, 2024). (4) Sovereign Gold Bonds (SGBs): 100% tax-free on redemption at maturity with RBI.
Cost of Improvement refers to capital expenditure incurred by the taxpayer to make additions or substantial alterations to the asset. Under Section 55, any improvement expenditure incurred prior to April 1, 2001 is completely ignored (as it is subsumed in the April 1, 2001 FMV valuation). Any improvement incurred on or after April 1, 2001 is indexed using the CII of the financial year in which the improvement was made: Indexed Cost of Improvement = Actual Improvement Cost × (CII of Sale Year / CII of Improvement Year).
Taxpayers can legally eliminate or reduce their LTCG tax liability by utilizing statutory exemptions: (1) Section 54: Reinvest LTCG from the sale of residential house property into purchasing another residential house (within 1 year before or 2 years after sale) or constructing one (within 3 years), capped at ₹10 Crore. (2) Section 54EC: Invest capital gains into specified long-term infrastructure bonds (REC, PFC, NHAI, IRFC) within 6 months of sale, up to a maximum limit of ₹50 Lakh per financial year (5-year lock-in). (3) Section 54F: Reinvest the net sale consideration from any long-term asset other than a residential house (e.g., land, gold, shares) into a residential house.