Stock Average Price Calculator

How it works

• Average price = Σ(price × quantity) ÷ total quantity. Fees are excluded.
• Averaging down lowers your break-even price but increases your exposure to one stock.

FAQ

How do I calculate my average stock price?

Add up price × quantity for each purchase, then divide by the total number of shares.

Worked example

Example: you buy 100 shares at ₩70,000 and then 50 more at ₩55,000. You spent ₩9,750,000 on 150 shares, so your average price is ₩65,000.

Target average: to bring a ₩70,000 average on 100 shares down to ₩62,000 while the price is ₩55,000, you need (70,000 − 62,000) × 100 ÷ (62,000 − 55,000) ≈ 114.3, so 115 more shares — about ₩6.3 million.

Why the average matters: your average price is your break-even point before costs. At ₩65,000 average, selling at ₩65,000 returns your money minus commissions and the 0.20% transaction tax, so the real break-even is slightly higher. Keep a record of each purchase, because Korean brokers show the average for the whole account, not per purchase lot.

Common mistakes

• Broker apps may include buying commissions in the average price, so their figure can differ by a few won.
• Selling part of a position does not change the average price of the remaining shares; only your realised profit changes.
• Averaging down lowers your break-even price but increases how much you hold of one stock — and your risk.
• For foreign shares, your average in won and in dollars move differently because of the exchange rate.
• Dividends received do not lower your average purchase price in Korean broker apps.

Explanation checked on 2026-10-30 · Spotted an outdated value? Tell us