ClarityHow to use this tool
- Enter first point: x, first point: y, second point: x, second point: y, target x.
- Select Calculate to view the result.
- Check the method and assumptions below before using the result.
Input reference and sample values
Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.
| Input | Format and units | Sample |
|---|---|---|
| First point: x | Numeric value. | 0 |
| First point: y | Numeric value. | 0 |
| Second point: x | Numeric value. | 3 |
| Second point: y | Numeric value. | 4 |
| Target x | Numeric value. | 1.5 |
Result for these sample inputs
2
- Slope
- 1.33333333
- Position
- Interpolation inside interval
- Fraction through interval
- 0.5
Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.
The method, explained
y = y₁ + (x − x₁) × (y₂ − y₁) ÷ (x₂ − x₁). A target outside the two known x coordinates is extrapolation.
Halfway between (0, 0) and (3, 4), x = 1.5 gives y = 2.
What to keep in mind
The relationship is assumed linear between the supplied points. Extrapolation is calculated but labeled because the same trend may not continue. Equal x coordinates are rejected.
Common questions
Can the known x values be in reverse order?
Yes. The calculation works in either order.
Is this a best-fit regression?
No. It connects exactly two points; it does not estimate a trend from a dataset.
Methodology maintained by ClarityKit. How these tools are built and checked.