Calculating your cost basis per share is straightforward once you know the Cost Basis formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the Cost Basis Calculator.
What is Cost Basis?
The Cost Basis calculation tells you your cost basis per share from a few simple inputs. The figure you are solving for here is the cost basis per share, expressed in INR.
The Cost Basis formula
The core formula is:
Cost basis per share = (Total amount invested + Fees & charges) ÷ Number of shares ÷ unitsHere is what each input means:
- Total amount invested — a money amount. Example: ₹10,000.
- Fees & charges — a money amount. Example: ₹100.
- Number of shares/units — a number. Example: 100.
How to calculate it step by step
- Write down the total amount invested (for example, ₹10,000).
- Write down the fees & charges (for example, ₹100).
- Write down the number of shares/units (for example, 100).
- Apply the formula above to get your cost basis per share.
- Double-check the result with the Cost Basis Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Total amount invested | ₹10,000 |
| Fees & charges | ₹100 |
| Number of shares/units | 100 |
| Cost basis per share | ₹101.0000 |
| Total cost basis | ₹10,100.00 |
With total amount invested of ₹10,000, fees & charges of ₹100 and number of shares/units of 100, the cost basis per share works out to ₹101.0000.
Example 2
With total amount invested of ₹20,000, fees & charges of ₹100 and number of shares/units of 100, the cost basis per share works out to ₹201.0000.
| Result | Value |
|---|---|
| Cost basis per share | ₹201.0000 |
| Total cost basis | ₹20,100.00 |
Example 3
With total amount invested of ₹5,000, fees & charges of ₹100 and number of shares/units of 100, the cost basis per share works out to ₹51.0000.
| Result | Value |
|---|---|
| Cost basis per share | ₹51.0000 |
| Total cost basis | ₹5,100.00 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
- Annual rates must be converted to the period you are calculating for (for example, divide an annual rate by 12 for a monthly figure).
Prefer not to do the maths by hand? — the Cost Basis Calculator does it instantly, for free, with the formula and a worked example built in.
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