Privacy Policy

The short version

The numbers you type into a calculator — on exactcalcs.com or inside a calculator embedded on someone else's site — are computed entirely in your own browser and are never sent to our servers. We don't run any analytics or advertising trackers. The data we do collect is limited to what's described below, and it's either required to operate an account you create or is aggregate usage data with nothing tied to an individual visitor.

What never leaves your browser

Every calculator's math (calc.ts in our source) runs client-side — height, weight, income, medical history answers, loan terms, whatever a calculator asks for. None of it is transmitted to us, on exactcalcs.com or through an embedded widget on a third-party site.

If you fill in the optional profile (age, sex, height, weight, activity level, income, expenses) that pre-fills fields across calculators, that's stored in your browser's local storage only. It's never sent to our servers, and it's cleared if you clear your browser's site data. A third-party site embedding one of our calculators cannot read or write this profile — the embed runtime doesn't load the code path that touches it at all.

One exception worth calling out: if you use a calculator's "Share this scenario" button, the values you'd entered are encoded into the URL you copy — treat a shared link as containing whatever you typed, since it isn't private the way the profile above is.

If you create a developer account

Signing up at exactcalcs.com/dev to get an API key, we store:

• Your email address.
• Your password, as a one-way bcrypt hash — we cannot see or recover the password itself.
• A name, if you provide one.
• If you sign in with Google or GitHub instead: the email address and name that provider gives us. We never receive your Google or GitHub password.

This is used to operate your account, your API key, and your trial/billing status — nothing else.

Widget and API usage data

When a calculator embedded on a third-party site loads, that visitor's browser sends your API key, the domain it's running on, and which calculator was requested, so we can verify the key is valid and registered for that domain. We keep an aggregate count of requests per API key and per calculator (for your own dashboard's usage/analytics cards) — not a log of individual visitors, IP addresses, or what they entered.

IP addresses are processed transiently to enforce per-minute rate limits on our API; they are not written to our database.

Email

We send account-verification email (and, if you ask for it, a resend) via our mailbox provider. We don't send marketing email, and we don't share your email address with anyone except that mailbox provider, who sees it only as the message's recipient.

Who else sees this data

• Our hosting and network provider, which is infrastructure everything above passes through.
• Our email mailbox provider, to deliver verification email.
• Google or GitHub, only if and when you choose to sign in with one of them.

We don't sell data, and we don't use any third-party analytics, advertising, or tracking service.

Deleting your data

Email [email protected] to delete your account and everything tied to it (email, password hash, API keys, registered domains, saved widget configuration). Your local browser profile is deleted any time by clearing that browser's site data for exactcalcs.com — we have no copy of it to delete on our end.

Children

ExactCalcs is not directed at children, and developer accounts are not intended for anyone under 16.

Changes to this policy

If this changes, we'll update the date at the top of this page. Continuing to use ExactCalcs after a change means you accept the updated policy.

Contact

Questions about this policy: [email protected].