Finance tools
Stock average calculator
Free stock average calculator for when you buy the same stock more than once. Enter each purchase (shares and price per share) to get your weighted average share price, often used as a simple cost basis on the position, plus total investment and optional unrealized gain or loss at a current price. See an average down example with presets, a purchase breakdown table, live formula, and CSV/PDF export — no sign-up. Not safety stock (inventory planning). Not a substitute for broker tax lots or IRS reporting.
What is a stock average price?
Your stock average price — also called average share price or average stock price — is the weighted average of what you paid on each buy. Bigger lots pull the average more than small ones. Many investors use it to track cost basis on a single stock, ETF, or fund before fees, splits, or tax adjustments.
One purchase: average price is simply that buy’s price. Two or more: use weighted math, not the average of the prices alone. For example, 100 shares at $50 and 50 at $40 is not ($50 + $40) ÷ 2 = $45; the correct result is $46.67 per share ($7,000 ÷ 150 shares).
Multi-buy purchase table
Add up to 20 buys with shares and price per share — fractional shares supported.
Live weighted average
Total cost, total shares, and average price update as you type — no submit button.
Unrealized gain or loss
Add an optional current price to see market value and paper profit or loss in dollars and percent.
CSV/PDF export
Download inputs and results for Excel, Google Sheets, or tax prep notes — no sign-up.
After you sell, model return with our ROI calculator. For a quick P/E check, use the P/E ratio calculator. For fair value vs price, try the intrinsic value calculator. For steady contributions over time, see the compound interest calculator.
Stock average calculator formula
Weighted average cost per share
Average price = Total cost ÷ Total sharesTotal cost = Σ (shares × price per share) for each buy.
Example: 100 shares at $50 and 50 shares at $40 → total cost $7,000 on 150 shares → average $46.67 per share.
With current price P: Market value = Total shares × P · Unrealized gain = Market value − Total cost
Your break-even price per share (before fees and taxes) equals the weighted average — the price at which unrealized gain is zero.
Cost basis vs average share price
In conversation, cost basis on a position often means the blended average share price you paid across your buys — what you would compare to a sale price before fees and taxes.
On tax forms, adjusted cost basis may differ. Brokers can adjust for splits, dividend reinvestment (DRIP), wash sales, and return of capital. You may also choose specific lots when you sell instead of a single blended average.
This tool shows weighted average cost from the purchases you enter. For filing, rely on your broker’s tax reports. More detail in cost basis for taxes below.
Average down calculator example
Averaging down means adding shares at a price below your current average, which lowers your cost per share when the new lot is priced under that average. Tap the Average down example preset (100 shares at $50, then 50 at $40) or use the table:
| Stage | Holdings | Total cost | Average price |
|---|---|---|---|
| After 1st buy | 100 shares @ $50 | $5,000 | $50.00 |
| After 2nd buy (avg down) | 150 shares (100 @ $50 + 50 @ $40) | $7,000 | $46.67 |
| At current price $55 | 150 shares | Cost $7,000 · Value $8,250 | Unrealized gain $1,250 (~17.9%) |
The average moved from $50 to $46.67 because the second buy was half the size of the first. A larger purchase at $40 would pull the average down further — enter your own lots in the calculator to see the effect.
Multiple small lots example
When you scale in with several small purchases at different prices, weighted average still applies. The calculator preset Six-buy example uses six one-share lots (prices $85, $84, $83, $75, $77, $75.50) — total cost $479.50 on 6 shares → average $79.92 per share.
At a current price of $100, market value is $600, unrealized gain about $120.50 (~25.1% vs average cost). That is the same math whether lots are 1 share or 100 — only the weights change.
Averaging up (buying above your current average) works the same way: new lots above your average raise the blended cost. Enter your real rows above; the purchase table shows each line cost.
Average down vs dollar-cost averaging
Averaging down means buying more shares after the price drops, which lowers your average cost if the new price is below your current average. This calculator shows the math after each buy.
Dollar-cost averaging (DCA) usually means investing a fixed amount on a schedule regardless of price. For scheduled contribution growth, see our compound interest calculator — this page focuses on actual share purchases you enter.
| Averaging down | Dollar-cost averaging (DCA) | |
|---|---|---|
| Trigger | You buy more after a price drop | Fixed amount on a calendar schedule |
| Goal | Lower average cost per share on a position you already hold | Reduce timing risk across many buys |
| This tool | Enter each lot — see weighted average update live | Not a DCA scheduler — enter lots manually or from statements |
| Risk note | Can increase exposure to a falling position | Does not guarantee profit; reduces timing concentration |
Neither approach guarantees a profit. This calculator only totals the purchases you enter — it does not recommend trades.
Stock average calculator in Excel or Google Sheets
To replicate this stock average calculator in a spreadsheet, put shares in column A and price per share in column B. Line cost in column C: =A2*B2 (fill down). Total cost = SUM(C:C); total shares = SUM(A:A); average price = total cost ÷ total shares.
One-cell weighted average (Excel / Google Sheets): =SUMPRODUCT(A2:A20,B2:B20)/SUM(A2:A20). Replace ranges with your row count.
Prefer the calculator above for up to 20 live rows, a breakdown table, and CSV export — then paste into your model. PDF export works for a printable snapshot.
Cost basis for taxes — what this tool does not do
Brokers may report adjusted cost basis after stock splits, wash sales, dividend reinvestment (DRIP), return of capital, and transfers between accounts. This calculator uses only the prices and shares you enter — it does not replace Form 8949 lot matching, specific identification, or broker tax reports.
- FIFO, LIFO, or specific lots — tax sales may use a method different from a simple weighted average.
- Wash sales — disallowed losses can adjust basis on replacement shares.
- Splits and reverse splits — share count and per-share basis change; enter post-split numbers or adjust manually.
For educational context, see Investor.gov — cost basis.
ETFs, mutual funds, and crypto
The same weighted average formula applies to ETFs, mutual fund accumulation units, and many crypto spot purchases — as long as you enter each buy as units × price in USD (or your quote currency).
Tax treatment, wash sales, staking rewards, and exchange reporting differ by asset and country. This tool does not fetch live quotes or sync to brokers; it is for manual cost tracking and education only.
Common stock average mistakes
- Simple average of prices — averaging $50 and $40 to get $45 ignores that you own twice as many shares at $50.
- Ignoring commissions — add fees to your price per share or line cost if you want all-in average cost.
- Mixing tickers — average price is per security; do not combine different stocks in one calculation.
- Confusing with safety stock — inventory buffer units for warehouses, not share purchases.
- Confusing with margin of safety — value-investing discount to fair value, not cost averaging.
- Using average for tax without checking — your broker’s reported basis may already include adjustments you did not model here.
Stock average vs safety stock and similar terms
These phrases sound alike but measure different things. Use this table to find the right Ordio tool:
| Term | Meaning | Use this tool? |
|---|---|---|
| Stock average / average share price | Weighted average of your buy prices | Yes — enter purchases above |
| Cost basis (informal) | Often the same as average cost per share on a position | Yes — with tax caveats below |
| Safety stock | Extra inventory units (warehouses) | No — safety stock calculator |
| Margin of safety | Fair value vs market price (value investing) | No — margin of safety calculator |
| Profit margin | Profit ÷ revenue on a product or business | No — profit margin calculator |
| ROI on a sale | Return after you sell vs amount invested | No — ROI calculator |
Limitations
Track one stock, ETF, or fund at a time. There is no ticker search, live quote feed, or automatic currency conversion — enter prices yourself in one consistent currency.
The tool does not apply FIFO/LIFO rules, DRIP adjustments, wash-sale logic, or broker tax lots. It also does not solve “how many shares must I buy to reach a target average?” — only the average from lots you list.
When you sell, use your average (or broker cost basis) in the capital gains tax calculator to estimate federal short- or long-term tax on the gain.
For education and personal records only — not investment, tax, or legal advice. Examples use USD; the formula works the same in any currency if every lot uses it.
How to use this stock average calculator
1. Enter purchases — Type shares and price per share from your trade confirmations. Click Add purchase for up to 20 rows. Presets fill an Average down example, Six-buy example, or Single lot so you can see how results look before editing.
2. Optional current price — Add today’s price per share to see market value and unrealized gain or loss. Skip this if you only want average price and total investment.
3. Read results — Average price per share and break-even price appear at the top; the purchase breakdown table shows each line cost. The formula card updates with your live totals.
4. Export — Save CSV for Excel or Google Sheets, or PDF for printing. No account needed. Numbers stay in your browser — we do not store them.
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Frequently asked questions about this stock average calculator
How do you calculate stock average price?
Average price = total cost ÷ total shares. For each buy, multiply shares × price per share and add those amounts for total cost; add the share counts for total shares. Example: 100 shares at $50 and 50 at $40 → $7,000 ÷ 150 = $46.67 per share. Use the calculator above for live results.
What is the stock average calculator formula?
Total cost = Σ (shares × price per share). Average price = total cost ÷ total shares. With a current price, unrealized gain ≈ (total shares × current price) − total cost. The on-page formula card fills in your totals automatically.
What is a cost basis calculator?
A cost basis calculator shows what you paid per share across several buys. This stock average calculator is that kind of tool: enter each purchase to get weighted average share price and total investment. It does not replace broker tax lots or IRS-adjusted basis.
Is this stock average calculator free?
Yes. The calculator, presets, purchase table, and CSV/PDF export are free with no sign-up.
Do I need an app to calculate average stock price?
No app required. Open this page in a browser on phone or desktop, enter your buys, and see the weighted average instantly. Export to a spreadsheet if you want an offline copy.
What is cost basis vs average share price?
On a position, average share price is often what people mean by informal cost basis. For taxes, adjusted cost basis on Form 1099-B can differ after splits, DRIP, wash sales, or specific-lot sales — confirm with your broker and tax advisor.
What is an average down calculator?
An average down calculator shows how a new buy below your current average changes your cost per share. Use the Average down example preset here (100 shares at $50, then 50 at $40) to see the average drop to $46.67.
What is averaging down?
Averaging down means buying more shares at a lower price than your current average, which lowers your cost per share when the new lot is priced below that average.
What is the difference between averaging down and dollar-cost averaging?
Averaging down is an extra buy after a price drop on a position you already hold. Dollar-cost averaging (DCA) is investing on a schedule. Both change your average cost over time, but the trigger is different — see the table on this page.
Does this calculator support fractional shares?
Yes. Enter decimal share amounts (for example 1.25 shares). The weighted average uses the exact quantities you provide.
Does the calculator include brokerage fees?
Not automatically. Roll commissions into the price per share for that lot (for example, add $0.05 per share when a $0.50 fee applies to 10 shares).
Is this the same as IRS cost basis?
Not always. This tool is a weighted average from your entries. IRS reporting may use specific lots or broker adjustments — see Investor.gov — cost basis for background.
Is this a safety stock calculator?
No. Safety stock is warehouse inventory buffer, not share prices. For inventory planning, use our safety stock calculator.
Is this related to margin of safety in value investing?
No. Margin of safety is how far price sits below your fair value estimate. This page averages what you paid on past buys. For MOS %, use our margin of safety calculator.
Can I use this for ETFs or crypto?
Yes for the same weighted-average math on units you bought. Tax and reporting rules vary by asset and country — this is not tax advice.
How do I calculate stock average price in Excel?
Use =SUMPRODUCT(A2:A20,B2:B20)/SUM(A2:A20) for shares in column A and prices in column B, or divide total cost by total shares. Or export CSV from this calculator and open it in Excel or Google Sheets.
Is this the same as profit margin on a stock?
No. Profit margin is profit ÷ revenue for a business. Here you are finding average purchase price across your own buys — not a company’s margin.
Can I export results to CSV or PDF?
Yes. Export CSV for Excel or Google Sheets, or PDF for a printable summary. No email required.
Do you store the numbers I enter?
No. Calculations run locally in your browser. We do not send your purchase data to a server to compute the average.