Stock Average Price Calculator

Calculate average cost, total shares, break-even price, and profit or loss after multiple stock purchases.

Average cost inputs

Combine existing holdings with a new purchase to estimate average cost and break-even price.

New average price

$42.01

Total shares

150

Total cost basis

$6,302

Unrealized result

-$2

-0.03% at current price

Estimated new fees

$1.8

Average cost change

-6.64%

Compared with the old average price.

Existing cost

$4,500

New purchase cost

$1,802

Market value

$6,300

Related calculators

What is the stock average price calculator?

This calculator combines multiple stock purchases into an average cost, then compares it with the current price to estimate unrealized profit, return, and partial-sale results. It supports averaging down, regular accumulation, and staged profit-taking.

Average-cost formulas

Core calculation

  • Average price = total purchase amount / total shares.
  • Unrealized profit = current price x total shares - total purchase amount.
  • Return = unrealized profit / total purchase amount x 100.
  • Most broker apps keep the average purchase price unchanged after a partial sale, while realized profit is calculated separately.
  • Fees and taxes may be included or excluded depending on broker settings, so compare the same basis when checking statements.

Watering down example

  • First buy: KRW 50,000 x 20 shares = KRW 1,000,000.
  • Second buy: KRW 45,000 x 20 shares = KRW 900,000 after a 10% drop.
  • Third buy: KRW 40,000 x 10 shares = KRW 400,000 after a 20% drop.
  • Total cost is KRW 2,300,000, shares are 50, and the average price is KRW 46,000.
  • At a current price of KRW 48,000, market value is KRW 2,400,000, profit is KRW 100,000, and return is about 4.35%; the first purchase alone would still show a 4% loss.

Strategy examples

Dollar-cost averaging

Four purchases of KRW 100,000 x 10, KRW 105,000 x 10, KRW 95,000 x 10, and KRW 98,000 x 10 produce total cost KRW 3,980,000 and 40 shares. The average is KRW 99,500. At KRW 110,000, value is KRW 4,400,000, profit is KRW 420,000, and return is 10.55%.

Partial profit-taking

If 200 shares have an average cost of KRW 30,000 and the current price is KRW 38,000, selling 100 shares produces KRW 3,800,000 proceeds and about KRW 800,000 realized profit before fees and tax. The remaining shares still use the KRW 30,000 average.