How to use Linear Interpolation Calculator
- Enter one x,y point per line with distinct x values.
- Enter the x value to estimate and choose whether extrapolation is allowed.
- Inspect the two points used and the resulting y value.
Example: Linear Interpolation Calculator
Linear Interpolation Calculator: At x = 5, y = 10.
Options
- Bracketing points
- Supply distinct x values. The page sorts them and uses the adjacent points around the query for a piecewise straight-line estimate.
- Extrapolation
- Enable this only when you intend to extend the nearest end segment outside the entered x range.
Supported inputs and limits
Where your input is processed
This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.
A segment between measurements is still an assumption
The output names the points used, so you can check whether that segment fits the task. Curved relationships and abrupt changes can make a straight-line estimate poor. Extrapolation extends the same assumption beyond the observations without adding evidence or uncertainty bounds.
Questions about Linear Interpolation Calculator
Does the input order matter?
The tool sorts points by x. Duplicate x values are refused because they do not define one y value at that location.
What happens at an entered point?
The result uses that point’s supplied y value.
Is extrapolation as reliable as interpolation?
It extends the nearest end segment beyond the observed range. That linear assumption can be poor, so it requires a separate choice.