StockCalc

Stock Average Calculator

Add every buy to see your weighted average share price instantly — then plan the next move with the averaging-down tool. Free, private, and works offline.

Your purchases

Average price per share

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Total shares

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Total invested

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Buy prices vs your average

Enter at least one buy to see the breakdown.

Your inputs stay in this browser — nothing is uploaded.

Averaging-down planner

Enter today's price and your target average — it tells you exactly how many shares to buy and the cost, using the totals above.

Fill both fields to see the plan.

How to use this calculator

  1. Enter each purchase. For every time you bought the stock, type the number of shares and the price you paid per share.
  2. Add more buys if needed. Use Add another buy — there's no limit on entries.
  3. Read your average instantly. The weighted average price, total shares, and total invested update as you type.
  4. Check the chart. Each bar is one of your buys; the line marks your overall average, so you can see which purchases pull it up or down.
  5. Plan the next buy. Use the averaging-down planner to find exactly how many shares at today's price would move your average to a target.

Note: This tool is for information and education only, not investment advice. Markets are unpredictable — always do your own research before buying or selling.

Frequently asked questions

What is a stock market average calculator?

A stock market average calculator works out the weighted average price you have paid per share across multiple purchases of the same stock. It multiplies each purchase's quantity by its price, adds those amounts together, and divides by the total number of shares.

Does averaging down reduce my loss?

Averaging down lowers your break-even price, so the stock needs a smaller recovery for your position to return to profit. It does not reduce the loss on shares you already own, and it increases the money you have at risk, so it should only be used on companies you still believe in.

How many purchases can I add?

You can add as many buy entries as you need. The calculator recalculates the weighted average instantly every time you add, edit, or remove a purchase.

Can I use this for crypto, ETFs, or mutual funds?

Yes. The maths works the same for any asset bought in units — stocks, ETFs, mutual funds, gold, or cryptocurrency. Enter the units you bought and the price per unit for each purchase.

Is my data stored or sent anywhere?

No. All calculations run entirely in your browser. Nothing you type is uploaded, tracked, or stored on a server, and the app even works offline once loaded.

How is the average price different from the break-even price?

The average price is purely what you paid per share. Your true break-even also includes brokerage, exchange fees, and taxes, so it is usually slightly higher than the average. This calculator shows the raw weighted average — add your transaction costs on top for an exact break-even.

What happens to my average when I buy more shares at a lower price?

Your average moves toward the new, lower price in proportion to how many shares you add. The more shares you buy at the lower price relative to what you already hold, the closer your average gets to that price — but it can never go below it.