How it works
For line ax + by + c = 0, perpendicular distance is |ax₀ + by₀ + c| / √(a² + b²).
Input definitions
- Line coefficient a
- Enter the value in the labeled unit.
- Line coefficient b
- Enter the value in the labeled unit.
- Line coefficient c
- Enter the value in the labeled unit.
- Point x
- Enter the value in the labeled unit.
- Point y
- Enter the value in the labeled unit.
A worked example
- Line coefficient a
- 3
- Line coefficient b
- 4
- Line coefficient c
- 0
- Point x
- 0
- Point y
- 5
Assumptions & limits
Uses the units and scope stated in the input labels. Results are rounded for display; verify the model is appropriate for your situation.
Sources & review
Maintained by AnsRio. Methods and examples use automated checks; this does not imply independent professional certification.
Method updated 2026-10-18. Content checked against the stated method and examples. Our verification approach.
Common questions
Can a vertical line be used?
Yes. Use b = 0 and a nonzero coefficient a. Both coefficients cannot be zero because that does not define a line.
How does Distance from a point to a line work?
For line ax + by + c = 0, perpendicular distance is |ax₀ + by₀ + c| / √(a² + b²).
What should I check before using Distance from a point to a line?
Uses the units and scope stated in the input labels. Results are rounded for display; verify the model is appropriate for your situation.