Nothing you measure leaves your browser.
There is one exception, it only happens when you press a button, and it is described in full below.
Your calculations
Every calculator runs entirely in your browser. The measurements you enter, the prices you add, and the results are never transmitted anywhere. There is no account and no sign-in, because there is nothing to sign in to.
Saved and recent calculations are stored by your own browser, on your own device. Clearing your browser data deletes them, and we cannot see them or recover them. Sharing a result creates a link that carries the numbers in the address itself — the link works because the numbers are in it, not because anything was stored on a server.
Reporting a problem
This is the one place where information leaves your browser, and only when you pressSend report. It goes to a shared intake we use for every site we run, so a problem reported here reaches the same place as one reported anywhere else.
What is sent and stored:
- What you write in the description box
- Which page you were on — the path only, never the full address
- The category you chose
- An email address, only if you choose to give one
- The calculation on screen, only if you tick the box that offers it. It is unticked by leaving it unticked; nothing is attached silently.
What is not stored:
- Your IP address
- Your browser or device details
- Where you came from
- Any identifier of any kind, and no cookies are set
Your IP address is used briefly to stop the form being flooded with automated submissions, and is never written down.
Because the page address is sent as a path and not a full URL, the query string is left behind. On this site that matters: a shared result carries your measurements in the query string, and a report should not smuggle them along when you did not ask it to.
Analytics
This site uses Cloudflare Web Analytics to count visits. It sets no cookies, stores nothing on your device, and does not attempt to identify you or follow you between sites. What it records is the page you viewed, the site you arrived from, your rough location at country level, your browser and device type, and how quickly the page loaded.
It is served by Cloudflare, which means loading it makes a request to Cloudflare — so this is the one part of the site that involves a third party at all. Your IP address is used to work out the country and is not stored against the visit.
If product analytics are enabled on top of that, they record which calculators are used and whether a calculation completed. They never receive your measurements, your prices, the name you gave a project, an email address, or any free text you wrote. That restriction is enforced in code by an allow-list, not by convention.
Advertising
No advertising is running on this site. If that changes, this page changes with it, in the same release.
Changes
If what we collect ever changes, this page is updated in the same commit as the change itself, rather than afterwards.