List of Online Graphing and Scientific Calculators

It happens to every high school and college student at some point: you forget to bring your calculator. Luckily, if you have computer or phone with Internet access, you can take advantage of free online calculators. The list below will set you up with the perfect calculator for your needs, whether you are trying to finish your physics lab report or your finance homework.

Online Graphing Calculator: This is by far the most versatile online graphing calculator I have found, and inputting the functions is very intuitive. In case you aren't sure how to enter a function, there is a pdf instruction manual too. When you click on the "Click to Start GCalc" button, a graphing window with a coordinate plane pops up. Above the coordinate plane is an input box where you can type the function with x as the variable. After you type the function, hit "Enter" and the graph will appear. You can plot multiple functions and manage them by clicking on the "Function List" button.

Online Graphing Calculator with Derivatives: This graphing calculator is a little buggier than the first and not as pretty, but it has one-click derivatives. If you enter a function f(x) to be graphed, it will also solve for the first, second, and third derivatives of the function. This is a great tool for checking (or cheating on!) your calculus homework.

Free Online Scientific Calculator: If you need to compute the value of complicated expressions like (exp(cos(5+pi))-Log(88))*Log(67)+sqrt(77), this calculator can do the job with accuracy up to 12 decimal places. Besides the usual exponential, logarithm, and trig functions, this calculator also has several built-in specialty functions. For example, the area(x,y,z) function computes the area of a triangle with side lengths x, y, and z. The gcd(x,y) function computes the greatest common denominator of two integers.

Matrix Calculator:For linear algebra and matrix operations, use this calculator to find the transpose, inverse, determinant, eigenvalues, eigenvectors, and decomposition. In the text field, enter the elements of the matrix with spaces between each element. Hit enter to start a new row. Once you have filled out the matrix, check the boxes for each item you want to compute, and hit the "Calculate" button.

Online 3-D Surface Graphing Calculator: To graph equations in 3-dimensional space, use this calculator to generate the image of a surface. The calculator accepts inputs in the form z = f(x,y), for example, z = x^2 + y^2, which is a paraboloid. You can spin the 3-D plot to view the surface from several angles.

See my related article, Top 10 Online Calculator Collections. Each website on the list has hundreds of practical application calculators that do everything from solve differential equations, estimate the amount of wood needed to build a hardwood floor, to estimating pregnancy due date and finding the distance between two cities.

Most PCs and Macs have a built in calculator with basic functionality. You can also use Excel to perform calculations. If you need to draw geometric figures based such as points, lines, conic sections, and polygons, there is a free to download program called GeoGebra that has an easy to use interface for creating simple geometry diagrams.