Slope measures steepness: rise over run. It is used for graphs, roads, roofs and ramps.
How to use the Slope Calculator
- x₁
- y₁
- x₂
- y₂
Results update as you type, and every field accepts the units shown in its menu.
How it works
Divide the change in y by the change in x. The intercept follows by substituting one point.
Inputs explained
| Field | What to enter |
|---|---|
| x₁ | A number |
| y₁ | A number |
| x₂ | A number |
| y₂ | A number |
What each result means
- Slope (m) = ([y₂] – [y₁])÷([x₂] – [x₁])
- y-intercept (b) = [y₁] – [Slope (m)]×[x₁]
- Angle of incline = deg(atan([Slope (m)]))
- Grade = [Slope (m)]×100
Example values
How the main result changes when x₁ changes and everything else stays at the example values above:
| x₁ | Slope (m) |
|---|---|
| 1 | 1.6 |
| 1.5 | 1.7778 |
| 2 | 2 |
| 2.5 | 2.2857 |
| 3 | 2.6667 |
| 4 | 4 |
Formula
m = (y₂ − y₁) ÷ (x₂ − x₁)b = y₁ − m x₁Worked example
Inputs — x₁: 2; y₁: 3; x₂: 6; y₂: 11.
Results — Slope (m) = 2; y-intercept (b) = -1; Angle of incline = 63.4349 °; Grade = 200 %.
Key terms
- Rise over run
- Vertical change divided by horizontal change.
Frequently asked questions
What does a negative slope mean?
The line falls from left to right.
What is the slope of a vertical line?
Undefined, because x does not change.
What formula does the Slope Calculator use?
m = (y₂ − y₁) ÷ (x₂ − x₁).