Privacy Policy

Calculations happen in your browser as you type. The numbers you enter are not transmitted to us, not logged and not stored — unless you are signed in and press Save, which is covered below.

This means a calculation you perform without an account leaves no record at all, including on our side. Closing the tab ends it.

An account stores:

• Your name, as you typed it. It is used to address you in the interface and in replies.
• Your email address, used to sign in, to verify the account, and to reset a password.
• Your password, stored only as a one-way hash. We cannot read it, and neither can anyone who obtained the database.
• An education level, if you chose one. It only sets sensible defaults, and it is optional.
• Dates: when the account was created, updated and verified.

We do not ask for a school name, a student ID, a date of birth, a phone number or an address, and there is nowhere to enter them. This site is used by minors, and the safest way to protect data is not to hold it.

Everything in this section is optional, is created only by your own actions, and is visible only to you:

• Saved calculations — the inputs you entered and the result, kept as a snapshot under a name you give it.
• Semesters and courses — course names, credit hours, grades and course levels you enter yourself.
• Academic profile — your current GPA, credits completed and degree requirement, if you enter them.
• GPA goals — a target, the credits you expect it to take, an optional date and your own notes.
• Custom grading scales — a scale you have defined, if your school's differs from the presets.

None of this is required to use the site, and none of it is shared. Access is checked on every request against the account that owns the record.

The contact form stores the name, email address, optional subject and message you send, so that we can reply and so that we can tell whether the same issue has come up before.

An error report stores which calculator it concerns, the type of problem, your description, and an email address only if you chose to give one. It is optional deliberately: reporting a wrong formula should not cost you an email address.

Both store a salted one-way hash of your IP address rather than the address itself. The hash lets us see that several messages came from the same place, which is what is needed to deal with abuse. It cannot be turned back into an address.

If you are signed in when you send either, it is linked to your account so a reply can go to the right place.

These cookies are necessary for the site to work at all:

• A session cookie, which keeps you signed in and which every page needs in order to protect its forms.
• A CSRF token cookie, which is what stops another site submitting a form on your behalf.
• A "remember me" cookie, only if you tick that box when signing in.

Google Analytics sets cookies of its own as well, which are not necessary — they exist so we can tell a returning visit from a new one. What it does and does not record is set out below.

There are no advertising cookies and no tracking pixels. Our own code writes nothing to your browser's local storage.

This site uses Google Analytics to count visits and see which calculators get used. It is switched on, and this is what that means.

What it records: which pages you visited, roughly where in the world you are, what kind of device and browser you used, and which of a short list of actions you took — opening a calculator, getting a result, copying or printing it, saving it, following a link to a guide.

What it never records: any number you typed. Not a grade, not a GPA, not a course name, not a credit total, not an attendance figure. The event says which calculator produced a result; it never says what the result was. Your email address and name are never sent.

Google Analytics sets its own cookies to tell a returning visit from a new one. Advertising features and ad personalisation are switched off entirely.

Google processes this data on our behalf and has its own privacy policy. Most browsers and several extensions can block it, and nothing on this site stops working if you do.

• We do not sell, rent or trade personal data. There is no arrangement under which that could happen.
• We do not share your data with third parties, except where we are legally required to.
• We do not use your saved calculations, courses or grades for anything other than showing them back to you.
• We do not send marketing email. Email from us is limited to account verification, password resets and replies to messages you sent.
• We do not track you across other websites.

• Account data is kept until you delete the account.
• Saved calculations, semesters, courses, goals and scales are deleted with the account, immediately and permanently.
• Contact messages and error reports are kept while they are useful — an error report is a defect record, and deleting it would lose the reason a fix exists. They are not linked to a deleted account.

• See it — everything stored about you is visible in your account.
• Change it — your name, email and password are editable in settings, as is every piece of academic data you have entered.
• Delete it — account deletion is in your settings and does not require contacting us. It removes the account and everything belonging to it.

Deletion is immediate and cannot be undone. If you want a copy of anything, take it first.

Passwords are hashed, never stored in a readable form. Every form is protected against cross-site submission. Every account record is checked for ownership on every request, so one account cannot reach another's data. Submission endpoints are rate-limited.

No system is perfectly secure, and it would be dishonest to claim otherwise. What we can say is that the amount of personal data held here is deliberately small, which limits what a breach could expose.

This site is used by school students, and it is designed on that assumption. That is the reason an account asks for so little, the reason calculations are not transmitted, and the reason IP addresses are hashed rather than stored.

If you are a parent or guardian and want an account removed, the contact form reaches us — though deleting it from the account's own settings is faster.

If what the site does with data changes, this page is updated before the change goes live rather than after it. The practices described here are the ones currently in effect.

Questions about any of it: get in touch.