WASPCalc is a free, privacy-first tool that does one thing exceptionally well — calculates your true average share price.
All calculations run in your browser. We never see your data.
No subscriptions, no registration, no paywalls.
Your weighted average updates instantly with every keystroke.
Every investor who dollar-cost averages or buys in multiple tranches faces the same problem: what is my actual average cost per share? Brokerage platforms either hide this figure or calculate it incorrectly using a simple average that ignores lot size.
We built WASPCalc because we were tired of opening spreadsheets to answer a question that should be instantaneous. The weighted average share price formula is straightforward — your cost per share should weight each purchase by the number of shares bought, not treat every transaction equally.
That formula is the heart of WASPCalc. Enter your purchase lots, switch currencies if needed, and your true break-even price is right there. Export to CSV for tax time and you're done.
WASPCalc is a calculation tool. It does maths. It doesn't give you advice on whether to buy, sell, hold, average down, or anything else. The weighted average it produces is a mathematical fact about your purchase history — what you do with that fact is entirely your decision.
We are not a financial adviser, broker, or investment platform. Nothing on this site should be treated as financial advice. For decisions involving real money, please consult a qualified financial adviser who understands your full circumstances.
The site is ad-supported via Google AdSense, which is how we keep it free. Ads are clearly labelled and we don't allow ads that interfere with the calculator or misrepresent financial products.
Questions or feedback? We'd love to hear from you via our contact page.
Free, instant, no sign-up required.