##### Related Content

# Slope Calculator

_{1}, y

_{1}), (x

_{2}, y

_{2}) =

## Lesson on Slope

#### Lesson Contents

### How do we Hand Calculate the Slope of a Line?

To calculate the slope of a line, we must either have its equation written in a slope form (such as slope-intercept form or point-slope form) or know two points along the line.

If the line is in a slope form, the coefficient *m* tells us the value of its slope. If we have two points along the line, we use the following slope equation:

The slope of a line tells us the average rate of change of a linear function between the two points being used. To find the slope of a non-linear function, we may calculate the derivative at a point.

For an in-depth lesson on finding slope and the average rate of change, see our lesson Average Rate of Change.

## How the Calculator Works

The slope calculator is written in the programming language *JavaScript* (JS). When you click the “calculate” button, the *slope* function is run by your internet browser’s JavaScript engine resulting in a nearly instant answer. The calculator does not require any communication to and from an external server which is why you do not wait on data transmission or a page reload for your answer.

The slope function utilizes the exact slope formula as given above. Your inputted *x* and *y* coordinates are plugged into the formula before the slope *m* is evaluated. If the raw slope output is in decimal format, it is rounded to the fourth decimal place. If not, it is left in whole number or fractional form. The final number is then displayed in the answer area.

When you click the “clear” button, all input fields are erased, and the calculator is reset. In some cases, the provided inputs do not allow for a solution to be found or cause an error in computations. When this happens, an error notice is instead displayed.