Online Calculators

Seriously, why would anyone want to look at yet ANOTHER online calculator? What's so special about the calculators here? Those are the questions so many of my friends posed when I announced my calculator construction project here at I've looked at a lot of calculators teaching math to the minions and playing with all things worksheet related, so I know. Certainly, yes, the Internet is adrift with calculators of every species imaginable, and in some cases those animals have proliferated with a shocking degree of virility.

But have you seen them? Ugly. Confusing. Bad. As in, 2005 just rang me up on a 56kbps modem and it's asking for its PHP forms and server-side CGI scripts to be returned.

So I was convinced. Something new, modern and amazing was needed, not just by me, but by calculator aficionados throughout the cyber-math sphere. There was a need for calculators that wouldn't just factor numbers, but factor them fantastically. A calculator that would make prime factorization fun again. A calculator for fractions that wasn't just cool, but visual and useful at the same time. And a fraction to percent calculator that was... Well, okay, that one is still not so entertaining.

Regardless, I hope you'll find this selection of online calculators useful. Click one of the links below, plug your favorite bits of numerical trivia into some of these online calculators and let me know what you think!

Prime Factorization Calculator

Online prime factorization calculator that produces the canonical prime factorization as well as a color factor tree. This is a projector-friendly online calculator for classroom factoring demonstrations.

Factoring Calculator

This cool factoring calculator produces color animated sets of factor pairs for integers and is great for classrom demonstrations.

Percentage Calculator

Percentage calculator for performing fraction to percent or percent to fraction calculations, as well as fraction to decimal conversions.

Fraction Calculator

Online fraction calculator for adding, subtracting, multiplying and dividing mixed and improper fractions.

Multiplication Calculator

Animated multiplication calculator that shows work for longer multiplication problems. Trying to understand multi-digit multiplication? This visual tool will help!


Online countdown timer with sounds. Great for classroom, cooking or other uses where you need to countdown to an event.

Age Calculator

Graphical age calculator that shows your chronological age in the context information about savings, U.S. Elections and more!

Long Division Calculator

Animated long division calculator that shows the work and steps required to divide with remainders.

Roman Numeral Converter

You will finally understand Roman Numerals! This VISUAL Roman Numeral Converter once and for all dispels the confusion Ceasar and Augustus cursed us with...

Instructions for Using the Online Calculators

Each of the online calculators on this page includes pop-up help that will appear if you do nothing when you start. The instructions will tell you what information the calculator needs to proceed and explain the results the calculator generates in the informational parts of the display. Each calculator also generates a dynamic link that you can save so that you can either return to the online calculator page with the exact problem you are viewing, or so that you can forward it to someone else.

Why Use Online Calculators Instead of the One on Your Desk?

Or the calculator on your phone? Well, all I can say is, give them a try. Unlike other tools you may find online, the calculators here are very specialized. Each of these online calculators is custom designed to solve the math problem at hand and attempt to provide a visualization. And each is responsive and mobile friendly.

Using Online Calculators With Projector or Smart Board

All of the calculators include a 'Zoom' button that hides much of the surrounding web page, making them projector or SmartBoard friendly! If you are in a teaching environment with a projector or a Smart Board, try clicking this button to see if the presentation is more appropriate in your classroom. If you save a link using the section at the bottom of each of these online calculators, it will remember this Zoom setting when you return.

More Online Calculators Coming Soon!

On the prowl for useful classroom or home school tools for teaching math? Check back at either the home page or at this URL for new calculators and other useful implements of math warfare. And no matter what you're calculating, be sure to browse through the collection of worksheets on the site, because as handy as using a calculator can be, when your internet is down, there's no substitute for being able to work those problems by hand.