# Stock Average Calculator

Calculate your average stock cost basis across multiple purchases. Enter up to 5 buys to find your weighted average price per share.

## What this calculates

Find your average cost per share after buying the same stock at different prices. Enter up to 5 purchases with shares and price per share, and the calculator will compute your weighted average cost basis.

## Inputs

- **Purchase 1 - Shares** — min 0 — Number of shares in your first purchase.
- **Purchase 1 - Price per Share** ($) — min 0 — Price per share for your first purchase.
- **Purchase 2 - Shares** — min 0 — Number of shares in your second purchase.
- **Purchase 2 - Price per Share** ($) — min 0 — Price per share for your second purchase.
- **Purchase 3 - Shares** — min 0 — Number of shares in your third purchase.
- **Purchase 3 - Price per Share** ($) — min 0 — Price per share for your third purchase.
- **Purchase 4 - Shares** — min 0 — Number of shares in your fourth purchase.
- **Purchase 4 - Price per Share** ($) — min 0 — Price per share for your fourth purchase.
- **Purchase 5 - Shares** — min 0 — Number of shares in your fifth purchase.
- **Purchase 5 - Price per Share** ($) — min 0 — Price per share for your fifth purchase.

## Outputs

- **Total Shares** — Total number of shares across all purchases.
- **Total Cost** — formatted as currency — Combined cost of all purchases.
- **Average Price per Share** — formatted as currency — Your weighted average cost basis per share.

## Details

Your average cost basis is the total amount you spent divided by the total shares you own. If you bought 50 shares at $100 and then 30 shares at $85, your total cost is $7,550 for 80 shares, giving you an average price of $94.38 per share.

Dollar-cost averaging (DCA) is a strategy where you buy a fixed dollar amount of stock on a regular schedule regardless of price. This naturally lowers your average cost over time because you buy more shares when the price is low and fewer when it is high. Tracking your average cost helps you see how DCA is working for you.

Your cost basis matters at tax time. When you sell shares, your capital gain or loss is based on the difference between the sale price and your average cost basis (for shares held in a brokerage account using the average cost method). Knowing your exact average cost helps you estimate tax liability before selling.

## Frequently Asked Questions

**Q: How is average stock price calculated?**

A: Add up the total cost of all your purchases (shares times price for each buy), then divide by the total number of shares. For example, buying 100 shares at $50 ($5,000) and 50 shares at $40 ($2,000) gives a total cost of $7,000 for 150 shares. Your average price is $7,000 / 150 = $46.67 per share.

**Q: Does averaging down always work?**

A: Averaging down (buying more shares as the price drops) lowers your cost basis, but it only works if the stock eventually recovers. If the stock continues to decline, you are adding to a losing position. Only average down on investments where you have strong conviction in the long-term fundamentals. Never average down just because a stock is cheaper.

**Q: What is the difference between average cost and FIFO for taxes?**

A: Average cost divides your total investment by total shares to get one cost basis. FIFO (first in, first out) assigns the cost of your earliest purchased shares to the shares you sell first. Mutual funds commonly use average cost, while individual stocks default to FIFO. Your broker typically lets you choose the method, but you should pick one and stick with it.

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Source: https://vastcalc.com/calculators/finance/stock-average
Category: Finance
Last updated: 2026-04-08