What's on the board.

This policy covers plankmath.com: what the calculators do with your measurements, what an optional account stores, what our payment and advertising partners see, and the choices you have. It is written to be read rather than to be survived.

1. Using a calculator, no account

Every calculator on this site — paint, flooring, decking, fencing, mulch, gravel, wallpaper and BTU — runs entirely in your browser. The dimensions you type, the coverage rates you adjust and the buy list that comes out are computed on your own device by JavaScript on the page. None of it is transmitted to us, and none of it is stored anywhere, unless you are signed in and explicitly choose to save a project.

You can verify this the same way you would verify any such claim: open your browser's developer tools, watch the Network tab, and run a calculation. Nothing goes out. You can also disconnect from the internet after the page loads and every calculator still works.

2. If you create an account

An account is optional and exists for one reason: to keep saved projects and calculations across visits and devices. If you create one, we store:

• Your email address, used to identify the account, send sign-in links and confirmations, and contact you about the account itself.
• Authentication credentials. Your password is salted and hashed before it is stored, and is never stored or visible in readable form.
• Projects and calculations you explicitly save — the calculator used, the inputs you entered, the resulting buy list, and any name or note you gave the project. Nothing is saved automatically; a calculation you do not save is not recorded.
• Account timestamps — when the account was created and last accessed.

Accounts and saved projects are held by Cloudflare, on Cloudflare's D1 database infrastructure. Their handling is governed by Cloudflare's privacy policy. Every query is scoped to the signed-in account, so an account can only read its own projects. Confirmation, password-reset and email-change messages are sent through Brevo, our transactional email provider — see Brevo's privacy policy.

Deleting your account from the settings page removes your account record and every project attached to it. This is immediate and permanent; we keep no shadow copy and cannot restore a deleted project for you.

3. Journeyman membership and payment

The paid Journeyman tier is billed through Stripe. Your card number is entered directly into Stripe's own hosted checkout and never touches our servers — we do not see, receive or store card details at any point. Stripe tells us only whether a subscription is active, when it renews and whether a payment failed, which is all we need to unlock the tier.

Stripe processes your payment information as an independent controller under its own privacy policy. Billing history and receipts live in your Stripe records rather than ours.

4. Advertising and cookies

PlankMath is free because it carries display advertising. Ads are hidden site-wide for signed-in Journeyman members; for everyone else they are served by third parties, which set cookies and similar technologies in your browser. Specifically:

• Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this website or other websites.
• Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this and/or other sites on the internet.
• You may opt out of personalised advertising at Google Ads Settings, or opt out of a third-party vendor's use of cookies for personalised advertising at aboutads.info/choices and, in Europe, at youronlinechoices.eu.
• If you have not opted out of third-party ad serving, cookies of other vendors or ad networks may also be used to serve ads on this site.

Advertising runs in its own frames and has no access to your measurements or your saved projects. Blocking these cookies does not break any calculator.

Calculator pages also carry affiliate links to home improvement retailers, marked with a paid-links notice above them. If you follow one and buy something, PlankMath may receive a commission from that retailer at no extra cost to you. Following the link hands you off to that retailer, whose own privacy policy governs what happens next; they may set their own cookie to attribute the sale. We are not told who you are or what you bought, and none of your measurements or saved projects are passed on. No quantity any calculator produces is affected by which shops are listed.

5. Other data we hold

• Server request logs. Our hosting provider records standard metadata for each request — IP address, user agent, referring page, timestamp — for security and aggregate traffic counts.
• Contact form messages. If you write to us, the message and your email are handled by Formspree, our form provider, and forwarded to us by email under its own privacy policy. Formspree holds the dashboard copy for up to 30 days and then ages it out automatically; the notification email in our inbox we keep only as long as answering you requires, and you can ask us to delete it sooner.
• Browser local storage. Calculators may remember your last-used units and a few preferences on your own device. That never reaches us.

We do not sell personal information, and we do not share your saved projects with anyone.

6. Your rights in the EEA and UK (GDPR)

If you are in the European Economic Area, the United Kingdom or Switzerland, you have the right to access, correct, delete, restrict or object to processing of your personal data, the right to data portability, and the right to complain to your national supervisory authority. Our lawful bases are: contract for operating an account and a membership you asked for; legitimate interest for security logging and aggregate traffic measurement; and consent for personalised advertising cookies, collected through Google's consent management platform before such cookies are set.

Account deletion is self-service in settings and takes effect immediately. For anything else, write via the contact page and we will act within 30 days.

7. Your rights in California (CCPA/CPRA)

We do not sell personal information for monetary consideration. Under the CPRA, third-party advertising cookies used for cross-context behavioural advertising may count as "sharing"; you can opt out through the links in section 4, or by enabling Global Privacy Control in your browser, which we honour. California residents may request disclosure or deletion of the personal information we hold — in practice your email, your saved projects and server logs.

8. Children

PlankMath is not directed at children under 13 and we do not knowingly collect their personal information. If you believe a child has created an account or written to us, tell us and we will delete it.

9. Security

The site is served over HTTPS. Every account query is scoped to the signed-in account itself, so one account cannot read another's projects, and card details never enter our systems in the first place. No system is perfect; if you find a security issue, the contact page reaches the developer directly and reports are welcome.

10. Changes and contact

Material changes to this policy will be reflected in the date at the top of this page. PlankMath is operated by Studio Ropewalk, LLC, a limited liability company registered in North Carolina, United States. Privacy questions and data requests go through the contact page and are answered within 30 days.