Privacy Policy

Last updated November 4, 2026. This policy covers asphalt-calculators.org and describes how the site works today.

Short version

• No account, no sign-up, no ads, and the site sets no cookies of its own.
• The sizes, depths, prices and settings you type are worked out in your browser and are never sent to us.
• We count visits and button use with our own analytics under a random ID. It never includes what you type. You can turn it off on this page, and browsers that send Global Privacy Control are never counted.
• A feedback message is stored only if you write one and press send.
• We don’t sell or share personal information, and we don’t use it for advertising.

Who we are

Asphalt Calculator at asphalt-calculators.org is run by Asphalt Calculator Studio (“we”, “us”). We decide what the site collects and why, so we are responsible for that data. To contact us about privacy, including any of the requests under “Your rights”, use the Give feedback button under the calculator’s result or on the contact page. There is no public email address.

What we collect at a glance

Using the calculator

Every calculation happens in your browser. The lengths, widths, depths, density, waste allowance, truck load and price you enter are not sent to our server, to our analytics or to anyone else.

While you work, the current job is kept in this tab’s session storage (key asphalt-calculator:job) so that reloading the page doesn’t lose it. Session storage belongs to the one tab, is never sent over the network and is deleted by your browser when you close the tab.

When you press Copy link or Share link, your inputs are written into the link after the # sign. Browsers don’t send that part of an address to a server when someone opens the link; it is only read by the page in their browser. Anyone you give the link to can see those numbers, so share it only with people you are happy to show them to. Copy the numbers puts a plain-text summary on your clipboard; nothing is sent anywhere unless you paste it somewhere yourself. Print uses your browser’s own print dialog.

Feedback you send

The Give feedback button opens a short form. Nothing is sent while you type. Only if you press send, we store:

• the message you wrote, exactly as you wrote it;
• this website’s domain (asphalt-calculators.org);
• the address of the page you were on, without any query string or # part;
• the time it arrived.

That is the message, the domain and the page path, nothing more. The form doesn’t ask for your name or email. If you want a reply, include a way to reach you in the message; we will use it only to answer you. To limit spam, the service keeps a one-way-hashed form of your network address for a short time so that no network can send more than 10 messages an hour. The hash can’t be turned back into your address. Please don’t include passwords, payment details or other private information in a message.

Analytics

We run our own first-party analytics to learn which features people use and where the site fails. It is not Google Analytics and it is not shared with any advertising network. Each event contains:

• the event type: a page view; time spent on the page and how far you scrolled; a click on a labelled button or menu (for example “Add another area”, “Copy link” or the shape menu); an area being added, with the number of areas; a result being worked out, with the number of areas and whether you used feet or meters; a change of units; a Gmm being applied; the numbers being copied; a link being copied or shared; the Print button; a shared link opening, and whether it was valid; or copying being blocked by the browser;
• the page path, without anything after ? or #;
• a random visitor ID, a random visit ID, a random event ID and the time.

It does not record any text or numbers typed into the calculator (sizes, depths, prices), the contents of a shared link, your name, your email, your IP address or anything else that identifies you. It doesn’t read your browser’s language, your screen size or the page you came from.

The visitor ID is kept in your browser’s local storage and the visit ID in session storage (keys starting with wa_). They are random, are not linked to any account and are not used on other websites. The analytics script is loaded from our Supabase project on every page, so Supabase receives your IP address and browser details when your browser fetches the script or sends an event, as any web server does, even if you have turned analytics off.

Turning analytics off deletes the visitor ID from this browser and stops all events. Your choice is remembered in local storage (key asphalt-calculator:analytics-off), so it applies only to this browser on this device. If you clear this site’s data, the choice is cleared too and you would need to turn it off again.

Cookies and browser storage

The site sets no cookies of its own. When your browser fetches the analytics script, Supabase’s network provider, Cloudflare, may attach a short-lived security cookie (__cf_bm, 30 minutes) that is used only to tell people from bots; many browsers block it as a third-party cookie. Otherwise the site uses your browser’s storage as listed below, and you can clear all of it at any time in your browser’s settings for asphalt-calculators.org.

Hosting and server logs

The servers that deliver these pages receive technical information with every request, such as your IP address, browser type and version, the page requested and the time. They may keep it in short-lived logs for security, abuse prevention and troubleshooting. The site is hosted by Vercel Inc.; see its privacy policy. Fonts and the photo on the home page are served from our own domain, so no font or image service sees your visit.

Service providers and transfers

Two service providers process data on our behalf, only for running this site:

• Vercel Inc.: hosting and delivery of the website.
• Supabase, Inc.: the databases that store analytics events and feedback messages, and the server that delivers the analytics script.

These providers may process data in the United States and in other countries where they or their sub-processors operate. Where the law requires it, such transfers rely on the providers’ standard contractual safeguards.

Why we may use the data

If you are in the European Economic Area or the United Kingdom, the legal bases we rely on are:

• Legitimate interests for analytics, server logs and the feedback limit: understanding how the site is used, fixing faults and keeping it safe from abuse. We keep this light by not recording what you type and by honoring opt-out and Global Privacy Control.
• Your choice to contact us for feedback: we store a message only because you decided to send it, and we use it to read and answer it.

The calculator data in your browser never reaches us, so we don’t process it. You can object to analytics at any time by turning it off above.

Sharing and selling

We don’t sell personal information, rent it or share it for targeted advertising, and we don’t combine it with data from other sources. Apart from the service providers above, we would disclose information only if the law required it, to protect the site or its users from fraud or abuse, or as part of a transfer of the site to a new owner, who would stay bound by this policy for data collected under it.

How long data is kept

• The job in progress: until you close the tab.
• Shared links: as long as the link exists wherever you put it; we never receive a copy.
• The analytics visitor ID and your opt-out choice: in your browser until you clear this site’s data.
• Analytics events: only as long as they help us improve the site, reviewed for deletion at least once a year. We may keep totals with no IDs in them (such as page views per day) for longer.
• Feedback messages: until they have been dealt with, and reviewed for deletion at least once a year.
• The hashed network address for the feedback limit: only for the rate-limit window.
• Hosting and provider logs: according to each provider’s retention period.

Security

The site is served only over HTTPS. Analytics events and feedback are written through narrow interfaces that accept new records but don’t let a visitor read anyone else’s data, and access to the stored data is limited to the people who run the site. Because we keep so little, there is little to lose, but no system is perfectly secure.

Your rights

Depending on where you live, for example under the GDPR, the UK GDPR or US state privacy laws, you may have the right to ask whether we hold information about you, to get a copy of it, to have it corrected or deleted, to restrict or object to how we use it, and to withdraw a choice you made. You won’t be treated differently for using these rights.

To make a request, use the feedback form and say what you want. Because we don’t collect names or accounts, we can usually only find a feedback message if you tell us roughly what it said and when you sent it, and we can only find analytics events if you give us the visitor ID from your browser’s storage (the wa_ key). Turning analytics off is the quickest way to stop further collection. We will answer within one month. If you are in the EEA or the UK, you can also complain to your local data protection authority.

US state privacy laws

In the past 12 months we have collected, as described above, internet activity on this site (analytics events and server logs) and the content of feedback messages people chose to send. We have not sold personal information or shared it for cross-context behavioral advertising, and we don’t use or disclose sensitive personal information. Residents of California and other states with similar laws can make the requests described under “Your rights”.

Global Privacy Control and Do Not Track

If your browser sends a Global Privacy Control signal, the analytics script doesn’t record anything, and there is no setting to change. There is no common standard for responding to the older Do Not Track signal. We don’t track you across other sites, so there is nothing for it to switch off, and you can still turn analytics off above.

Children

The site is a general-audience tool for estimating paving material. It is not aimed at children, and we don’t knowingly collect personal information from children under 13 (or under 16 in the EEA and the UK). If you believe a child has sent us personal information in a feedback message, tell us and we will delete it.

Links to other sites

The sources on the home page link to documents on other websites, and this page links to our hosting provider’s policy. Nothing is loaded from those sites until you click, and their own privacy policies apply once you are there.

Changes to this policy

We will update this page, and the date at the top, whenever the way the site handles data changes. If a change means collecting something new, we will describe it here before it starts.