Effective: September 25, 2026
Calcebra is a handwritten whiteboard math tutor with AI hints, checking, and chat. By using Calcebra, including trying the board as a guest, starting a student testing session, or creating an account, you agree to these terms and to the Privacy Policy. If you don't agree, please don't use it.
A student testing session opens from a testing link. It is not an account. To start one you enter a first name and accept these terms (you must be 13 or older). Your writing, checks, AI replies, button presses, comments, and a note about what specifically improved if you write one, are recorded so the session can be reviewed and Calcebra can be improved. A working copy of your board, including any problem photo you add, is kept so a refresh or a new tab can put you back where you were. A Prolific study link saves your Prolific IDs instead of a name. A separate, optional box lets your handwriting also be used to train handwriting recognition. The Privacy Policy explains what is saved.
Don't use Calcebra to:
Calcebra is built to help you learn, not to complete graded work for you. Follow your school's and your instructor's rules on using AI tools. You're responsible for how you use Calcebra's help on assignments, quizzes, and tests.
Hints, checks, chat answers, class-plan suggestions, and daily challenges are generated by Calgorithm, our AI system (built on Claude, via Anthropic's API), together with a handwriting recognizer and an automatic step checker. They can be wrong. Calcebra is a practice tool, not a substitute for a teacher, and its answers are not authoritative for graded work.
The tutor sometimes adds a short, playful reaction to a Check (for example, when a mistake repeats or when you fix it). Those lines are about the math, not about you, and they don't change whether your work is marked right or wrong.
If you check the box at signup or at the start of a testing session, or turn it on later in Account settings, Calcebra saves the raw pen strokes of equations you write (the coordinates and timing of your handwriting, not images or photos). It uses them to train and improve its own handwriting recognition, including building a dataset we may use commercially. Samples may be exported with the text the recognizer read, without your name, email, or account ID. This is off by default and optional. You can turn it off at any time in Account settings without losing access to anything. Turning it off stops new samples from being saved. It doesn't delete samples already saved unless you delete your account or ask us to (see the Privacy Policy).
Homework Session is available only when you are signed in. Guests cannot start one. Before it starts you must accept these Terms, the Privacy Policy, and a separate consent to store your handwriting for that session. Both agreements are required. There is no single "accept all" control for them. Handwriting storage in this mode is not the optional training opt-in above, and agreeing to it does not turn training on. We keep the written work so you can resume after closing the browser, move between problems, and export a PDF in the assignment's problem order. Discarding a session deletes that assignment's text and the stored handwriting. The Privacy Policy describes exactly what is stored and what a discard leaves behind.
What you write, type, upload, and ask stays yours. You give Calcebra permission to store, process, and send that content to the service providers listed in the Privacy Policy only as needed to run and improve the service, and, if you opt in, to use your handwriting as described above. The Calcebra application itself (its code, design, and branding) belongs to its creator.
We send account emails (address verification and password resets) and, if you save an assignment with a due date, reminders before it's due. We don't send marketing email.
Calcebra is provided "as is" and "as available," without warranties of any kind, including accuracy, fitness for a particular purpose, and uninterrupted or error-free operation. This is a small, actively developed project.
To the fullest extent the law allows, Calcebra and its creator are not liable for indirect, incidental, special, or consequential damages, or for lost grades, data, or opportunities, arising from your use of Calcebra. Calcebra is currently free. Our total liability for any claim relating to it is limited to the amount you paid us in the twelve months before the claim, which today is zero. Some places don't allow these limits, so they may not fully apply to you.
We may suspend or end access for anyone who violates these terms or puts the service or other users at risk. You can stop using Calcebra at any time and delete your account from the Account panel.
If these terms change in a material way, we'll update the effective date above and, where appropriate, show a notice in the app. Continuing to use Calcebra after a change means you accept the updated terms.
Questions about these terms: hello@calcebra.com
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