Stock Average Calculator
Combine the same stock held across multiple brokers
Enter the average price and current quantity already shown by each broker. The calculator combines those positions without rebuilding your trade history.
Use the same stock, currency, and share unit in every row. Currency is a label only; no exchange rate is applied.
Combined position
Combined average price
- Total quantity
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- Implied total cost
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- Market value
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- Unrealized gain / loss
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- Unrealized return
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Broker breakdown
How the result is calculated
Combined average = sum of (broker average price × current quantity) ÷ total quantity.
What this calculator does not recalculate
Each broker average is accepted exactly as entered. Fees, taxes, dividends, corporate actions, foreign exchange, and sold lots are not added again. A small difference from a broker can occur when its displayed average is rounded.
Why a simple average is wrong
Broker A shows 1,000 shares at 50 and Broker B shows 500 shares at 42. The correct result is (50 × 1,000 + 42 × 500) ÷ 1,500 = 47.333333, not (50 + 42) ÷ 2 = 46, because the two positions contain different numbers of shares.
Quick guide
What can Stock Average Calculator help you do?
Combine the average cost and current shares shown by multiple brokerage accounts. Get total shares, implied cost, weighted average, and optional unrealized return.
Best for
Use it when the same stock is split across two or more brokers and you want one combined average from the average price and current quantity each app already shows.
How to use it
Keep every row on the same stock, currency, and share unit. Enter each broker-displayed average and current quantity, then optionally add a current market price for a combined unrealized result.
How to read the result
The combined average is total implied cost divided by total quantity. The breakdown also shows each account’s implied cost and percentage of the combined position so you can check the inputs.
Privacy and limits
All holding values are calculated in your browser. Nothing is uploaded, no brokerage account is connected, and no live quote is requested.
The tool accepts each displayed broker average as entered and does not rebuild commissions, taxes, dividends, corporate actions, sold lots, or foreign exchange. Rounded display values can differ slightly from a broker’s internal cost basis.
Frequently Asked Questions
How do I combine stock averages from two brokers?
Multiply each broker-displayed average price by its current quantity, add those implied costs, then divide by the combined quantity. The calculator performs that quantity-weighted calculation for two or more accounts.
Should I add commissions and taxes again?
No. Enter each broker average exactly as displayed. If the broker already included fees in that figure, adding them again would double count them.
Can I combine different stocks or currencies?
No. Every row must represent the same stock, the same currency, and the same share unit. The currency selector labels results but does not convert values.
Why can the result differ slightly from my brokerage app?
A broker may calculate with more decimal places than it displays. Combining rounded displayed averages can therefore produce a small difference from a result based on the broker’s full internal values.
What does the optional market price calculate?
It estimates the combined market value, unrealized gain or loss, and unrealized return using the total current quantity. Leave it blank when you only need the combined average.
Are my holdings uploaded?
No. The calculation runs in your browser and does not connect to a brokerage account or send the values to a server.