Privacy

Analytics and cookie choices

We use Plausible and Google Analytics to understand which pages and tools are useful. Measurement includes page visits and actions such as using a tool or following a product link.

Tool events use fixed action categories. They do not include dimensions, formulas, lift limits, notes, owned equipment or contact messages.

Plausible counts every visit without cookies. It may receive browser and device information and a referring page.

Google Analytics is run by Google, which receives the page address, the actions we measure on this site and browser and device information, and sets cookies that tell repeat visits apart. Its advertising features are off.

Plausible gives us aggregate reports about page visits, referring pages, time spent and scrolling; we send it the page address without its query string or fragment, and its service also receives your IP address. We send Google the page address without its query string, fragment or referring address.

In the European Union, Iceland, Liechtenstein, Norway, the United Kingdom and Switzerland, and whenever we cannot tell which country a visit comes from, Google Analytics loads only after you choose Accept on the bar at the bottom of the page. Decline loads nothing from Google. Your choice is kept in this browser for six months, then the bar asks again.

Elsewhere, Google Analytics loads with each page unless you choose Decline. Cloudflare, which delivers our pages, tells your browser which country the visit comes from.

Wherever you are, Cookie choices at the bottom of any page, or the button below, changes your choice. Decline stops Google Analytics on this site in this browser and deletes its analytics cookies. If analytics was running, the page reloads to apply your choice. Decline holds on every page; outside the countries above it is kept until you change it.

Cookie choices

Cookies and local storage

This site sets no advertising cookies and no cross-site tracking cookies.

Plausible is cookieless. It counts visits without storing an identifier on your device.

Google Analytics sets first-party cookies that tell repeat visits apart, only where it is allowed to run: Analytics and cookie choices above says where it waits for your Accept. Your choice on the cookie bar is kept in a cookie of this site and in this browser’s storage.

Your saved setup uses this browser’s local storage. It stays on your device, it is not a cookie, it is never sent to us, and the Clear saved setup control removes it.

If you are in the EU, the EEA or the UK

We rely on legitimate interests to run aggregate, cookieless measurement of which pages and tools are useful.

Google Analytics sets cookies, so here it loads only after you choose Accept on the cookie bar. Decline, or no choice at all, loads nothing from Google, and Cookie choices at the bottom of any page changes your answer.

Our measurement and hosting providers are outside the EEA. Amazon (product images and product links) and our own Plausible instance receive connection information, including your IP address, when a page or an image loads; Google LLC (Google Analytics) receives it only after you accept. Standard contractual clauses cover the transfers our providers operate under.

You can ask us what we hold about you, ask for it to be deleted, or object to this measurement. Because we hold no account, no email list and no identifier for you, the practical answer is usually that there is nothing to return. Use the contact page and we will answer.

If a display advertising network is added to this site later, it will introduce its own vendors and its own consent request, and this page will say so before that happens.

The other companies involved

Cloudflare routes and protects the domain. Plausible Analytics (our own instance) measures page visits. Google Analytics measures page visits and tool use where it is allowed to run, as described above. Amazon serves product photographs at page load and receives the request when one is displayed. Amazon also records the referral when you follow one of our product links, which is how the site is funded.

Following any external product or source link opens a site with its own privacy practices. No purchase is processed here.

Your setup stays in this browser

Calculations run in the browser. The setup sheet saves only when you choose Save on this browser. It uses local storage on this device and can be deleted with the Clear saved setup control or browser storage settings. Printing and JSON export create output you choose to keep. There is no account or server copy of the setup.

Images and other websites

When an Amazon image is displayed, your browser contacts Amazon’s image service. Product prices and purchase details are handled by the shop you visit.

Contact messages

The contact form sends your report, your reply address and any page or source you add through Cloudflare. Cloudflare Turnstile runs an automatic security check that never asks you to solve anything; it receives your browser and connection details to tell people from automated senders.

We keep each report in our contact inbox at Cloudflare for 12 months, then it is deleted automatically, and a copy goes to a private Discord channel our team reads. We use your reply address only to answer you, never for marketing. To stop floods of messages, the form counts reports from one connection or reply address for two hours, under a one-way code rather than the address itself.

To see or delete a report you sent, ask through the same form and we will delete both copies. Please do not include passwords, account logins or payment details.