Stock Average Cost and FIFO Profit Calculator

How the calculation works

1. Average cost = total cost of shares bought (with fees) ÷ shares bought; each sale reduces holdings at that average.
2. FIFO matches each sale with the oldest lots first and charges their actual cost.
3. Unrealised profit = market value of the shares still held − their remaining cost.

Background and professional notes

What the calculator shows

The weighted-average acquisition cost is based on the quantity and cost of successive buys, including explicitly entered allowable purchase expenses. When a sale occurs, average cost is deducted from net sale proceeds to show an indicative weighted-average result. The second view tracks the oldest available purchase lots and computes a FIFO economic gain. Keeping both avoids conflating a broker portfolio average with the tax lot evidence required for certain dematerialised securities.

Work from your contract notes

Enter transactions chronologically using ISO dates (YYYY-MM-DD), with one transaction per CSV line. Quantity must be positive, and a sale cannot exceed available shares in the model. The example purchases 100 shares at ₹250 and 50 shares at ₹300, then sells 80 at ₹330. One-time fees are allocated to the purchase or sale shown; the engine does not silently insert taxes or other transaction charges.

What is excluded

This is not a final capital-gains return working. The model does not determine the holding period, wash sales, bonus/split effects, rights allotments, off-market transfers, FIFO rules for every account type, STT deductibility, tax slab, loss set-off, or grandfathering. Reconcile the rows against the securities ledger, demat statement, broker tax-P&L report and relevant law.

How to interpret the result

The remaining shares and capital employed can be combined with a manually entered current price to produce unrealised appreciation or depreciation. A gain is not cash until the position is actually sold. Brokerage, exchange charges and STT must be classified according to their actual nature; do not automatically include every trade levy in tax cost.

Evidence to retain

Keep contract notes, broker turnover statement, ledger entries, demat movement records, corporate-action notifications, acquisition documents and supporting price data. If a trade history is incomplete or includes transactions through multiple demat accounts, do not use the resulting average as a final tax figure.

Worked transaction example

Consider two purchases: 100 shares at ₹250 with ₹25 allowable buy expense, and 50 shares at ₹300 with ₹15 allowable expense. The combined book cost is ₹40,040 for 150 shares, an economic average of approximately ₹266.93 per share. A sale of 80 at ₹330, less ₹20 disposal expenses, generates net proceeds of ₹26,380. Under the pooled average method the realised P&L is approximately ₹5,025.33; under FIFO, the earliest 80 units have a cost of ₹20,020 and the economic gain is ₹6,360. The unsold 70 shares have an illustrative market value of ₹22,750 at a manually assumed quote of ₹325. These differences explain why separate basis methods must not be interchanged.

When not to use the output

The batch model assumes one security, one account, valid chronological trades and no share splits, bonuses, transfers, short selling, derivatives or corporate reorganisations. Broker statements sometimes present average cost for display even where the tax basis uses particular lot rules. Validate demat FIFO cost, timing of transfer and special grandfathering evidence separately. An incorrect fee classification is another common source of large returns discrepancies; securities transaction tax has its own capital-gains treatment.

Reconciliation checklist

Ensure opening holdings equal the closing balance of the prior broker statement. Match each contract-note number to trade dates and share quantities. Reconstruct corporate actions before beginning the calculation, verify whether fees are deductible, compare realised gains with tax P&L, and match unsold holdings with the depository closing balance. Keep the working as supporting evidence rather than treating the current quote as proof of profit.

Assumptions and what this calculator does not cover

• Two cost methods are shown for comparison. For tax, the cost basis follows the depository FIFO rule and your holding period; STT and non-deductible costs need separate treatment.
• Corporate actions such as splits and bonus issues are not adjusted.

Official sources and further reading

• Official source: Income Tax Department — sale of shares
• Official source: Income Tax Department capital-gains guide

Rates and rules were checked against these sources on 11 October 2026. Notifications and standards change; confirm on the official site before you file, book or advise.