Stock Average
Stock Average — runs in your browser. Inputs are not stored.
Stock average cost (for reference)
Enter values, then press Calculate.
※ Fees and taxes not included. For reference.
How to use
- In the buy-history box, write one line as
quantity price. Spaces, commas, or colons can separate them. The default sample is 100 shares at 50,000 KRW, 50 at 52,000, and 30 at 48,000. - Blank lines are ignored. Lines with quantity 0 or less, or non-numeric values, are skipped.
- Optionally enter current price (KRW). The default is 51,000 KRW. Leave it empty or 0 to hide total market value.
- Press Calculate to see total quantity, average cost, total buy amount, and total market value at the current price.
- Reset restores the three sample lines and current price 51,000 KRW. Fees and transaction tax are omitted.
Key concepts
The stock average-cost calculator is used for average cost, averaging down, and total buy amount for shares held. Average cost = total buy amount ÷ total quantity, and total buy amount is the sum of quantity × price on each line. A current price shows total quantity × current price as market value; there is no separate profit % field. It matches searches that want averaging-down cost, average buy price, and holding value without a brokerage app.
Fees, transaction tax, dividends, and FX fees are omitted. Folding fees into the unit price gets closer to a felt average. Overseas stocks work if the numbers match; convert currency yourself. The point is a quick check of whether average cost after averaging down is above or below the current price. Results are for reference and may differ from a brokerage balance or investment advice.
Example
100×50,000 + 50×52,000 + 30×48,000 → total 180 shares, buy amount 9.04 million KRW, average cost 50,222 KRW. At 51,000 current, market value is 9.18 million KRW, 140,000 above total buy. One line of 100 shares at 50,000 → average 50,000; at 51,000, market value 5.1 million KRW. Calculate with the on-screen defaults to match the figures above. Change a field and calculate again with the same rules. For real filings, payouts, and contracts, official notices and agreements take priority. These numbers are for reference.
Related: Percentage · Compound interest · Salary raise
Frequently asked questions
How many lines does the stock average-cost calculator accept?
Parsing runs in the browser, so a typical buy-history length is fine. Each line only needs two numbers: quantity and price.
Are fees included in the stock average cost?
No. Fold them into the unit price if you need that. For reference only.
Does dollar or overseas-stock average cost work?
Numbers only are enough. Convert currency yourself. For reference only.
Does the stock average calculator also show return %?
It shows total market value at the current price; compare that with total buy yourself for profit %. For reference only.
Does trade history remain on a server?
No. Calculation runs only in the browser. Buy history is not transmitted.
Is the stock average-cost calculator investment advice?
No. It is a simple average-cost calculation for reference. It is not a buy or sell recommendation.
Last reviewed: 2026-09-04