Stock Average Calculator
Estimate your weighted average stock cost basis after up to four purchases. Optionally compare it with a current market price.
| Metric | Value |
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Weighted average cost = total amount invested ÷ total shares purchased.
Informational only. Does not include commissions, taxes, spreads, or partial lot accounting rules.
How it works
The calculator multiplies each purchase quantity by its price, adds the totals together, and divides by total shares. That gives the weighted average cost per share.
If you enter a current market price, the tool also estimates unrealized gain or loss compared with your average cost basis.
Examples
- 10 shares at $50 and 15 shares at $45 → weighted average below $50
- Buying more at lower prices can reduce average cost
- Enter current price to estimate unrealized position value
When to use this tool
This tool is designed for quick, practical tasks such as everyday calculations, data formatting, or simple conversions. It is best used when you need fast results without installing software or using complex tools.
When to use
- Quick checks or one-time calculations
- Validating or converting data before using it elsewhere
- Simple tasks that do not require advanced software
When not to use
- Critical financial, legal, or medical decisions
- Large-scale or automated processing
- Situations requiring guaranteed precision beyond basic validation
Always review results before using them in important contexts.
About this tool
This tool helps you perform quick utility operations directly in your browser. It runs entirely in your browser without sending data to a server.
You can use this tool when handling simple tasks without installing additional software. The results should be interpreted as a processed output based on your input data.
FAQ
- What does this stock average calculator do?
It calculates your weighted average cost per share after multiple stock purchases at different prices.
- Why is weighted average cost useful?
It helps you understand your true average purchase price across multiple buy orders.
- Can I estimate unrealized gain or loss?
Yes. Enter the current price to estimate unrealized profit or loss.
- Does this include fees or taxes?
No. This version does not include commissions, taxes, or other trading costs.
- Are my trade inputs stored?
No. All calculations run locally in your browser and are not stored or transmitted.