What Is the Slope of a Line?
What Is the Slope of a Line?
The slope of a line is its steepness.
The larger the slope, the steeper the line.
Understanding the Slope of a Line
The slope of a line is how far the line goes up (or down) divided by how far a line goes across (left to right).
Look at the line below:
If we draw a triangle under the line and measure how far it goes up and across...

The line goes up by 3...

...and across by 3.
Slope = How far up ÷ How far across
Slope = 3 ÷ 3
Slope = 1
The slope of the line is 1.
Real Examples of the Slope of a Line

Lines that slope from the bottomleft up to the topright have a positive slope.
The line above has a slope of 2 because it goes up by 2 squares and across by 1.

Lines that slope from the topleft up to the bottomright have a negative slope.
The line above has a slope of −2 because it goes down by 2 squares and across by 1.

Lines that do not slope up nor down have a slope of 0.

Lines that do not slope across have an undefined slope.
Formulas to Find the Slope of a Line
We can find the slope of a line if we know how far it goes up and how far it goes across.
In Cartesian coordinates, the yaxis measures how far up a line is and the xaxis measures how far across a line is. This lets us define a formula to find the slope of a line:
Read more about finding the slope of a line
We can find the slope if we know two points (in Cartesian coordinates) on the line.