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Privacy Policy

This page explains, in plain terms, what happens to the dates and amounts you type into this site's XIRR calculator, and what this site collects (or doesn't collect) about your visit. Short version: every calculation runs entirely in your browser, nothing you type is sent to a server, and there is no account, login or tracking cookie on this site.

What happens to the numbers you enter

The XIRR calculator does its math entirely inside your browser, using JavaScript. Every date and amount you type, whether in the regular investments (SIP) mode or the irregular cash flows mode, is never sent to a server, never logged, and never stored in any database on this site. There is no form anywhere on this site that transmits your calculator inputs anywhere.

This is a direct consequence of how the site is built: it is a static site with no backend that receives, processes or stores what you type. There is no infrastructure on this site's side capable of receiving those numbers, even if someone wanted to.

Theme preference and saved calculator values

The only thing this site saves on your device is your light/dark theme preference and your last entered cash flow rows, stored in your browser's localStorage. This does not identify you, is never sent to any server, and only exists so the page can remember your inputs on your next visit. You can clear it at any time by clearing this site's data in your browser, or by using the Reset link under the calculator.

The feedback button

Below the calculator there is an optional thumbs-up / thumbs-down feedback button. Clicking it sends an anonymous signal (just the vote count, no information that identifies you, no stored IP address, no tracking cookie) to this site's backend, purely so the count can be tallied. A local marker in your browser prevents you from being asked to vote again repeatedly, but that marker does not identify you personally, it only stops a second vote from the same browser.

Anonymous engagement measurement

This site measures a small set of anonymous, aggregate engagement signals so the tool itself can be improved: how quickly a visitor starts interacting with the page after it loads, whether the calculator was actually used (a result was produced), whether a visitor left again within 10 seconds without interacting at all, and roughly how long a visitor stayed on the page (bucketed into ranges, not an exact duration). It also records a coarse category for where a visit came from (Google, Bing, a direct link, or "other"), never the full referring URL or any search terms.

None of this identifies you: there is no cookie, no session identifier, no stored IP address, and no browser fingerprinting anywhere in this measurement. Each page view is treated as a standalone, anonymous event sent once when you leave the page, using your browser's built-in sendBeacon mechanism to this site's own backend, not a third-party tracker. It cannot be linked back to a specific visitor, a specific device, or your calculator inputs.

Cookies

This site does not use advertising tracking cookies or third-party profiling cookies. The only local storage used is the localStorage mentioned above, for theme preference and calculator values, which is technically not a cookie and is not automatically sent to any server with every request, unlike a traditional cookie.

Hosting and infrastructure

This site is hosted on Cloudflare's network, which processes the technical requests needed to deliver the page to your browser (source IP address, browser type, request time), the same way any hosting provider does. That technical infrastructure data falls under Cloudflare's own privacy policy as the network operator, and is not accessed, exported or combined by this site to identify visitors individually.

Not financial or tax advice

Separate from privacy, one clarification worth stating plainly: the XIRR figure this site's calculator produces is a mathematical result based only on the dates and amounts you type in, not financial, investment or tax advice, and not a guarantee of any future investment return. No visitor data is used to generate this result; it is calculated fresh from your own inputs each time, with nothing remembered or personalised across visits beyond the local values described above.

What this site does not do

To be explicit rather than vague: there is no user account system, no login, no email newsletter signup, no advertising network, no remarketing pixel, no live mutual fund or market data lookup, and no sale or sharing of visitor data with data brokers. The XIRR calculator is the entire functionality of this site, and it does not require, request, or benefit from collecting personal information, so none is collected.

Changes to this policy

If the way this site collects or handles data changes in the future, for example if a new feature required saving something on a server, this page will be updated to reflect that change before it takes effect. There is no fixed review schedule, but the commitment is to keep this text matching what the tool actually does, not a generic description copied from elsewhere.

Who operates this site

Puffer AB
Flaggan 1338, 116 74 Stockholm, Sweden
Aktiebolag (Swedish limited liability company), registered with Bolagsverket (Swedish Companies Registration Office) (registration number 556850-9144, VAT ID SE556850914401).

Contact: contact@xirrcalculator.xyz

XIRR CalculatorEnter your dated cash flows, investments, top-ups and withdrawals, to get your annualised XIRR return instantly.XIRR vs CAGRA deeper side-by-side comparison, with worked numeric examples, of when XIRR and CAGR agree and when they diverge.XIRR in ExcelA step-by-step walkthrough for calculating XIRR in Excel or Google Sheets, with a worked example and common #NUM! error fixes.

Frequently asked questions

Do you store the dates or amounts I enter?
No. All calculation happens in your browser, in JavaScript. No date or amount you enter is sent to a server or saved in any database on this site.
Does this site look up my mutual fund or portfolio data?
No. The calculator does not connect to any live market-data source or brokerage account. You type in your dates and amounts directly; nothing is looked up automatically, and no fund name or account detail is collected.
Does this site use cookies?
It does not use tracking or advertising cookies. The only local storage is your theme preference and last entered cash flow rows, saved via your browser's localStorage, which is not a cookie and is not automatically sent to servers.
Does the engagement measurement identify who I am?
No. The anonymous engagement measurement described above (interaction timing, whether the calculator was used, and a coarse referrer category) uses no cookies, no session identifier, no stored IP address, and no fingerprinting, and does not build an individual profile per visitor.
Does this site share data with third parties for advertising?
No. There are no ad networks, remarketing pixels, or visitor data shared with third parties for advertising purposes. The only third-party infrastructure involved is hosting (Cloudflare), which is necessary for any site to function on the internet, described in the section above.
How do I contact you about a privacy question?
Use the feedback link under the calculator, or email contact@xirrcalculator.xyz.

XIRR Calculator (https://xirrcalculator.xyz)