This Privacy Policy explains how Tools Core treats information when you use the free calculators and converters published on this site. Tools Core is an independent project, not a company collecting customer accounts: there is no sign-up, no login, and no profile for us to build about you. The short version is that the tools themselves run inside your browser and keep your inputs on your own device, while the advertising we use to keep the site free relies on cookies served by Google. The sections below spell out exactly what that means and how to control it. This policy was last updated on 1 June 2026.
What the tools collect
Nothing leaves your device. Every calculator and converter on Tools Core — the mortgage and loan calculators, the BMI and salary tools, the unit and currency converters, and the rest — performs its work with JavaScript that runs locally in your browser. When you type a loan amount, a date, or a measurement into one of our tools, that value is used to compute a result on your screen and is never transmitted to a Tools Core server. We do not run a database, we do not store the numbers you enter, and we cannot see your calculations. There is no server-side application here to receive them: the site is a set of static pages served from a content delivery network.
Because the tools are client-side, closing the tab or refreshing the page clears whatever you entered. We do not ask for your name, your email address, or any other personal detail in order to use a tool. The one place we invite you to contact us — the Contact page — is entirely optional and only collects what you choose to put in an email to us.
Cookies and advertising
Tools Core is free to use, and we cover the cost of building and hosting it through advertising. We use Google AdSense to display ads on the site. To make that work, Google and its partners place and read cookies in your browser.
Third-party and DoubleClick cookies
Third-party vendors, including Google, use cookies to serve ads based on your prior visits
to Tools Core and to other websites across the internet. These advertising cookies may be
associated with Google's doubleclick.net domain or with country-specific
Google domains such as google.com. They are set by Google's ad systems rather
than by Tools Core directly, and they allow the ad network to recognise a browser across
the sites it serves.
Personalized advertising
Google's use of advertising cookies enables Google and its partners to serve personalized ads — advertising chosen for you based on your visits to this site and other sites you have been to. Personalized advertising means the ads you see are tailored to your inferred interests rather than shown at random. If you would prefer not to receive personalized ads, you can turn them off using the opt-out controls described in the next section; you may still see ads afterwards, but they will not be tailored to you.
For visitors in the European Economic Area, the United Kingdom, and Switzerland, applicable law requires consent before personalized-advertising cookies are used. Where that consent is requested, you will be asked to make a choice before such cookies are set, and you can change your decision at any time using the same opt-out links below.
How to opt out
You are always in control of the advertising cookies in your browser. You can review and switch off personalized advertising from Google directly, and you can opt out of interest-based advertising from many companies at once through industry programs:
- Manage your Google ad personalization at Google Ads Settings: https://www.google.com/settings/ads. (Google now presents these controls through My Ad Center at https://myadcenter.google.com/ as well.)
- Opt out of interest-based advertising from participating companies through the Digital Advertising Alliance at https://optout.aboutads.info/ (also reachable via https://www.aboutads.info/choices/).
- Visitors in Europe can use Your Online Choices at https://www.youronlinechoices.eu/.
You can also block or delete cookies in your browser's settings at any time. Doing so does not affect the calculators and converters, which work the same whether or not advertising cookies are present.
More about Google's data practices
Google's collection and use of data when serving ads is governed by Google's own policies.
You can read how Google uses information from sites that use its services in the
Google Privacy Policy, and learn more
about advertising cookies on Google's
advertising technologies page.
Tools Core authorizes Google as a seller of its ad inventory; that authorization is declared
publicly in the site's ads.txt file.
Children's privacy
Tools Core is a general-audience reference site and is not directed at children under 13. We do not knowingly collect personal information from children, and because the tools do not collect personal information from anyone, there is nothing for us to delete on request.
Changes to this policy
We may update this Privacy Policy from time to time, for example if we change how the site is monetized or add new tools. When we do, we will revise the “last updated” date at the top of this page. Significant changes will be reflected here rather than announced individually, since we have no mailing list to notify.
Contact
If you have a question about this policy or want to exercise a data right under the GDPR, the CCPA, or another applicable law, you can reach us through the Contact page. We will respond to legitimate requests as promptly as we reasonably can.