Line Equation Calculator
Determine the equation of a line through two points in slope-intercept and standard forms.
Inputs
Line Equation
y = 2.0000x + 0.0000
Slope (m)
2.0000
Y-Intercept (b)
0.0000
Step by step
Slope
m = (8 − 2) / (4 − 1)
= 2.0000
Equation
= y = 2.0000x + 0.0000
How it works
Given two points, the slope is m = (y₂−y₁)/(x₂−x₁). The slope-intercept form is y = mx + b, where b = y₁ − m·x₁.
Formulas
Slope
m = (y₂ − y₁) / (x₂ − x₁)
- x₁,y₁
- First point
- x₂,y₂
- Second point
Slope-Intercept Form
y = mx + b
- m
- Slope
- b
- Y-intercept
Frequently Asked Questions
What if the line is vertical?
Vertical lines have undefined slope. The equation is simply x = constant.
How do I convert to standard form Ax + By = C?
Rearrange y = mx + b to get −mx + y = b, then multiply through to clear fractions if needed.