Finance & Investment
Stock Average Calculator
Stock Average — it computes your weighted average cost per share = total amount invested ÷ total shares bought. This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
Stock Average Calculator is a browser-based way to work out your average cost per share. Feed it your buy lots and it computes the weighted-average buy price and total position on the spot, keeping your data local.
Estimate only. Not financial, investment, tax, retirement, pension, crypto, or legal advice. Returns, rates, fees, taxes, inflation, market prices, product rules, and government schemes can change. Verify with official sources or a qualified professional before relying on results.
About this calculator
Get stock average right and the rest of the task gets easier. It computes your weighted average cost per share = total amount invested ÷ total shares bought. It matters any time money changes value over time — savings, loans, investments, prices and pay all reduce to these relationships. Buying 10 shares at 100 and 20 at 130: average cost = (1,000 + 2,600) ÷ 30 = 120/share . The tool above does the same computation in your browser — free, private, nothing stored.
How to use
- List each purchase on its own line as a quantity and a price.
- Add a separate line for every lot you bought at a different price.
- Check that each line has both a quantity and a price.
- Tap Calculate to see the average price, total shares, and total invested.
Why use the Stock Average Calculator
Instant
Every figure is computed on your device the moment you tap Calculate.
Private
Your numbers stay in your browser; nothing is sent to a server or saved.
Free
No signup, no paywall, and no ads placed inside your results.
Works offline
Once the page has loaded it keeps working even on a weak connection.
Mobile-first
Laid out for phones and tablets just as much as for desktops.
Honest estimates
Uses simplified formulas for educational estimates; actual results vary with taxes, fees, compounding rules, market returns, scheme rules, inflation, and local regulations.
Common uses
Use it when adding to a position
Stock Average in trade and investment journaling
Use it when averaging down on a holding
Use it when planning further purchases
Use it for quick average-cost maths
Use it when reviewing multiple buy lots
Technical notes
Stock Average Calculator computes your weighted average cost per share = total amount invested ÷ total shares bought.
Uses the buy lots (price and quantity) you enter to compute your average cost; it excludes brokerage and taxes unless a field asks for them.
Because it runs locally, results appear instantly with no server round-trip.
Worked example
Buying 10 shares at 100 and 20 at 130: average cost = (1,000 + 2,600) ÷ 30 = 120/share.
FAQ
How is the average price calculated?
It is a weighted average: the total amount invested across all lots is divided by the total number of shares bought, not a simple average of the prices.
Does the Stock Average Calculator send my data to a server?
No. The Stock Average Calculator runs entirely in your browser with JavaScript; the values you enter never leave your device and nothing is uploaded or saved.
How do I enter several purchases?
Put each buy lot on its own line in the box as quantity then price, for example 10, 100 on one line and 20, 80 on the next.
Does this include brokerage or charges?
No. It averages the prices you enter only; brokerage, taxes, and other charges would raise your true average cost.