Privacy Policy
Short version: calculator inputs never leave your browser, we run no analytics that identify you, and the only cookies on this site come from Google AdSense after you accept them. The long version is below, in plain English.
The short version
factonisam is operated as a static website. There is no application server, no database and no user account system. That architecture decides most of this policy: there is nothing here capable of receiving, storing or analysing the values you enter into a calculator.
| Data | Collected? | Where it goes |
|---|---|---|
| Numbers you type into a calculator | No | Processed in your browser; never transmitted |
| Your name or email address | Only if you email us | Our inbox, and nowhere else |
| Theme, favourites, recent tools | Stored by your own browser | localStorage on your device |
| IP address and user agent | By our hosting provider | Standard web-server logs, retained short-term |
| Advertising identifiers | By Google, only after you accept | Google's advertising systems — see below |
What happens to the numbers you type
Every calculation on this site runs as JavaScript inside the browser tab you have open. When you type a salary, a weight or a loan balance, that number becomes a variable in your browser's memory, is used in an arithmetic expression, and is written back to the screen. It is not sent to us. It is not written to any database. It is not included in any log. When you close the tab it is gone.
This is not a promise we are asking you to take on trust — it is a property of how the site is built, and you can verify it. Open your browser's developer tools, switch to the Network tab, and use any calculator on the site. You will see requests for the page, the stylesheets, the scripts and the fonts, and no request carrying your values.
One consequence worth knowing: if you use the Share link button on a calculator, the values you entered are placed into the URL so the recipient sees the same calculation. That link is created on your device and copied to your clipboard. Where you paste it is up to you — but be aware that a shared link contains the numbers you typed, so think before pasting one into a public channel.
What your browser stores locally
The site stores four small items in your browser's localStorage. This is storage that belongs to your browser on your device; it is not transmitted with requests the way cookies are, and we cannot read it from our side.
| Key | What it holds | Why | Cleared by |
|---|---|---|---|
fs-theme | "light" or "dark" | So the site opens in the mode you chose | Clearing site data |
fs-consent | "accepted" or "rejected" | So the cookie banner does not ask again | Clearing site data |
fs-recent | Up to 12 calculator names | To offer recently used tools | Clearing site data |
fs-fav | Calculator names you starred | To show your saved tools | Clearing site data |
None of these identify you. They contain no name, no email address and no identifier that could be linked to a person. They also do not follow you between devices, which is why your starred tools appear on your laptop but not on your phone.
Advertising, Google AdSense and third-party cookies
This site carries advertising supplied by Google AdSense, and that is the one place where third-party data collection happens. It is gated: the AdSense script is not loaded at all until you press Accept on the consent banner. If you press Reject non-essential, no advertising script is injected and no advertising cookie is set.
If you do accept:
- Google, as a third-party vendor, uses cookies to serve ads on this site.
- Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
- You may opt out of personalised advertising at any time by visiting Google Ads Settings.
- You can opt out of personalised advertising from many other vendors at aboutads.info/choices and the NAI opt-out page.
- Third-party vendors and ad networks other than Google may also serve ads through Google's systems and set their own cookies.
Opting out of personalised advertising does not remove advertising; it makes the ads you see less specific to you. Google's own handling of that data is governed by how Google uses information from sites that use its services, which sits outside this policy. To change your choice on this site, clear your browser's site data for factonisam.com and the banner will ask again.
Hosting, fonts and server logs
Our hosting provider records the ordinary information any web server records when it answers a request: the IP address the request came from, the time, the page requested, the referring page and the browser's user-agent string. These logs exist to keep the site available and to identify abuse, they are retained for a short operational period, and they are not combined with anything else to build a profile of you.
Fonts are loaded from Google Fonts, which means your browser makes a request to fonts.googleapis.com and fonts.gstatic.com. Those requests carry your IP address and user agent to Google in the same way any request to any server does. No calculator values are involved.
We do not run Google Analytics or any other visitor-tracking product on this site.
Your rights
If you are in the UK or European Economic Area (UK GDPR / GDPR)
The lawful bases we rely on are legitimate interests, for operating and securing the site, and consent, for advertising cookies. You have the right to access personal data we hold about you, to have it corrected or erased, to restrict or object to processing, to data portability, to withdraw consent at any time, and to lodge a complaint with your national supervisory authority. In practice, the only personal data we are likely to hold about you is an email you sent us; ask and we will delete it.
If you are in California (CCPA / CPRA)
We do not sell or share personal information as those terms are defined by the CCPA, and we do not receive payment for personal information. You have the right to know what we collect, to request deletion, to correct inaccurate information, and not to be discriminated against for exercising any of these rights. Email us to exercise them.
Children's privacy
factonisam is a general-audience reference site and is not directed at children under 13. We do not knowingly collect personal information from children. If you believe a child has sent us personal information, email us and we will delete it.
Retention
Emails you send us are kept while the conversation is useful and then deleted. Server logs are retained for a short operational period by our host. Everything else described here lives on your own device and is under your control.
International transfers
The site is served from a content delivery network with servers in many countries, so the page you are reading may have been delivered from outside your own. Google's advertising infrastructure likewise operates internationally.
Changes to this policy, and how to reach us
When this policy changes materially we will update the review date at the top of the page and, where the change affects how data is handled, note it here. Continued use of the site after a change means you accept the revised policy. This version was last reviewed in August 2026.
Questions, requests or complaints about privacy go to info@factonisam.com. If you would like a specific item deleted, tell us what it is and we will confirm when it is gone.