Calc21 Calculus in the 21st century

Tools

Free calculus tools: a tour by the job you need done

Sixteen tools that cost nothing to use, sorted by what you actually need: graph it, check an answer, give the class something to do, or have it explained again. One sourced line each — and nothing ranked.

By Calc21 · 8 min read · checked 14 October 2026

This is the short route through the free end of our resource library. It is not a list of the “best” anything: on a page like this that word is a claim we cannot honestly make, and which tool earns its place depends on your class, your board and the hour of the evening. So the tour is organised by the job instead.

One rule held everything below together. Every factual sentence comes from the tool’s own page, is quoted where the wording matters, and carries the date it was checked. We have no affiliation with any of these sites, no affiliate or referral links, and nothing here was paid for or sponsored. Where a tool has a paid tier we say so in the same breath, because a free tier that quietly expires is worse than no free tier at all.

Graph it

The job: a student needs to see the shape before the symbols mean anything.

Desmos Graphing Calculator — type the equation, see the shape

Desmos Studio describes itself as “a Public Benefit Corporation with a goal of helping everyone learn math”, and says its “free suite of math tools, including our Graphing Calculator, is used annually by over 75 million people around the world.” The calculator opens onto a blank graph and plots straight away — no account needed to draw, an account only to save. desmos.com/calculator

GeoGebra Calculator Suite — graph, geometry, algebra and 3D in one window

GeoGebra’s licence page says GeoGebra “and our web services are made available free of charge for non-commercial users”, and notes that “most of our users are students and teachers”. The Calculator Suite keeps the graphing view, the geometry view, a 3D view and a computer-algebra window side by side. Worth knowing: that licence is for non-commercial use, so commercial work needs a licence of its own. geogebra.org/calculator · licence details

Math Insight — applets for the ideas that will not sit still

Math Insight describes itself as “a collection of pages and applets designed to shed light on concepts underlying a few topics in mathematics”, with “the focus … on qualitative description rather than getting all technical details precise”, and adds that many pages “were designed to be read even before students attend lecture”. It is at its strongest on multivariable ideas — partial derivatives, the divergence of a vector field — where a static diagram stops working. mathinsight.org

Check an answer — and see what the machine misses

The job: you want to know whether the answer is right, and to show students the difference between a computed result and a justified one.

Wolfram|Alpha — ask in plain English, get a computed answer

Type a limit, derivative or integral in ordinary words and it computes and plots the result. Its pricing page lists a Basic Account as “free with sign-in” — and states plainly that the free level does not include step-by-step solutions — with a paid Pro tier adding “step-by-step solutions, increased computation time and calculator Web Apps”. So: free answers the question, the worked walkthrough is the part you pay for. wolframalpha.com · pricing

Wolfram MathWorld — the precise statement, with its references

Wolfram Research describes MathWorld as “provided as a free service to the world’s mathematics and internet communities” — a reference of 15,337 entries (last updated 2 October 2026) assembled over more than 25 years by Eric W. Weisstein with thousands of contributors. Its entries, such as Derivative, close with a “See also” list and a references section, which is what makes it useful when a textbook’s wording is not quite enough. mathworld.wolfram.com · about

Practise it, or set it

The job: the class needs reps, a second explanation, or a worksheet for tomorrow morning.

Khan Academy — AP Calculus AB practice, free with an account

The AP Calculus AB course page carries practice and video by unit. Khan Academy’s own prompt to teachers reads “Sign up free to assign practice, track progress, and more”, and its sign-up flow offers “Create a free account as a … Teacher” — so assignments and progress tracking come with a free account. khanacademy.org/math/ap-calculus-ab

Paul’s Online Math Notes — full course notes, chapter by chapter

Paul Dawkins’s notes cover complete courses for Calculus I, II and III, plus Algebra and Differential Equations, laid out the way a syllabus is, with practice problems and worked solutions. It reads without an account, and the calculus pages are long enough to teach from. tutorial.math.lamar.edu

Math Medic — free discovery-based AP Calculus lesson plans

Its AP Calculus course page answers the question in its FAQ directly: “Every AP Calculus lesson plan, activity, and answer key is free with a Math Medic account”, and “lessons are free”. Math Medic Plus is a paid yearly teacher subscription that “builds on the free lessons” — so the free account is the course, and the subscription is the extras on top of it. mathmedic.com/course/ap-calculus

Ximera — Mooculus: the text and the exercises on the same page

MOOCulus, part of the Ximera project, presents Calculus One, Two and Three as browser-based courses with the exercises built into the reading rather than stapled on at the end. The site credits The Ohio State University together with an NSF grant (DUE-1245433) and the Shuttleworth Foundation. ximera.osu.edu/mooculus

Active Calculus — a free, open-source text built for active learning

Active Calculus describes its books as “free, open-source texts designed for an active learning experience for students”, available to read online with free PDF versions of each edition (print copies are sold separately). Every section carries activities for students to work through before and during class, and the licence lets you copy and modify the source. activecalculus.org

OpenStax — Calculus Volume 1, and its two siblings

OpenStax publishes its calculus text in three volumes; Volume 1 covers what its summary calls “functions, limits, derivatives, and integration”. The book is released under a CC BY-NC-SA 4.0 licence — the site’s words: “free to use and adapt, but not for commercial purposes” — and can be read online or downloaded as a PDF. The senior authors include Gilbert Strang of MIT, who is also one of our Who’s Who entries. openstax.org/details/books/calculus-volume-1

Math LibreTexts — a shelf rather than a book

LibreTexts describes itself as “the adaptable, user-friendly non-profit open education resource platform”, with more than 3,000 textbooks — including a Calculus bookshelf you can browse by topic and download page by page or as a full PDF. It is the fastest way to get a second explanation of one topic without committing to a whole course. math.libretexts.org/Bookshelves/Calculus

Kuta Software — the free worksheet library, with the paid product named

Kuta’s “Free Printable Math Worksheets for Calculus” page lists ready-made worksheets by topic, from limits at removable discontinuities to the definition of the derivative. The worksheets are generated with its commercial Infinite Calculus product, which the same page offers as a “Free 14-Day Trial” — the printable library is the free part, and it is there to print. kutasoftware.com/freeica.html

Watch it explained

The job: the lesson landed for half the room, and the other half needs to hear it another way.

3Blue1Brown — The Essence of Calculus

Grant Sanderson’s animated series is described on the page in his own words: “visual introductions to the core ideas of derivatives, integrals, limits and more”, an overview “with an emphasis on making it seem like something students could discover for themselves”. Free to watch; supporters, the site notes, “get early access to new videos”. 3blue1brown.com/topics/calculus

Mathispower4u — short videos, organised the way a course is

The site’s own summary: “This site provides over 9,000 free mini-lessons and example videos. All of the videos are closed captioned and ADA compliant … The videos are organized by course and topic.” Calculus I, II and III each have their own library, made by James Sousa. mathispower4u.com

MIT OpenCourseWare — 18.01SC, the whole course

Single Variable Calculus, taught by Prof. David Jerison in Fall 2010, is published in full: lecture videos, lecture notes, problem sets with solutions, exams with solutions and problem-solving videos. It is written for MIT undergraduates rather than AP students, which is exactly why it is good for your own prep. ocw.mit.edu — 18.01SC

What we are not claiming

We have no relationship with any of these sites: no affiliate links, no referral codes, nothing paid for, nothing sponsored. We have not ranked them or tested them against one another — which is why they are grouped by job and not numbered. And free tiers are not permanent: every claim above was read from the vendor’s own page on the date shown, and if something here has moved behind a paywall since, tell us and we will re-check it.

The resource library carries the longer list, with free and paid entries labelled and every link date-checked. This piece is the tour; that is the shelf.

Free, no spam

Get new articles by email

Roughly twice a month. Unsubscribe any time.

One email address is all we ask for. New articles, roughly twice a month, and nothing else.