Math and Education
Linear Interpolation Calculator
Linear Interpolation Calculator interpolate or extrapolate a y-value between two coordinate points at a selected x-value and report the line equation.
Math and Education
Linear Interpolation Calculator
Interpolate or extrapolate a y-value between two coordinate points at a selected x-value and report the line equation.
Formula
y = y1 + (x - x1)(y2 - y1)/(x2 - x1).
About the Linear Interpolation Calculator
Interpolate or extrapolate a y-value between two coordinate points at a selected x-value and report the line equation.
How the Linear Interpolation Calculator Works
The slope through two points is calculated once and applied to the target x; the result is labeled interpolation when x lies within the endpoint interval.
Formula
y = y1 + (x - x1)(y2 - y1)/(x2 - x1).
The calculation runs in your browser. Values are validated for required ranges, compatible units, and method-specific restrictions before results are displayed.
Required Inputs
- First x-value (required).
- First y-value (required).
- Second x-value (required).
- Second y-value (required).
- Target x-value (required).
Results Reported
The result panel reports the final answer and the intermediate quantities needed to check the calculation:
- Calculated y-value
- Line slope
- Line intercept
- Position from first to second x
- Interpolation or extrapolation
Linear Interpolation Calculator Example
Select Example Data in the calculator to load this reproducible input set:
| Input | Example value |
|---|---|
| First x-value | 10 |
| First y-value | 100 |
| Second x-value | 20 |
| Second y-value | 180 |
| Target x-value | 15 |
How to Use the Calculator
- Confirm that the calculator title and formula match the quantity you need.
- Enter every required value using the unit shown with its field.
- Select Example Data to inspect a valid input set, or enter your own values and select Calculate.
- Review all reported values and the displayed formula before using the answer.
- Use Copy Result or Download CSV when you need a reusable record.
Accuracy and Limitations
The two x-values must differ. Linear interpolation assumes the relationship is adequately straight between points; extrapolation outside the interval carries more uncertainty.
Keep units consistent, use measurements that represent the actual situation, retain full precision during the calculation, and round only the final answer. Professional decisions may require current official rules, field measurements, laboratory methods, or specialist review.
Frequently Asked Questions
What does the Linear Interpolation Calculator calculate?
Interpolate or extrapolate a y-value between two coordinate points at a selected x-value and report the line equation.
Which formula does the Linear Interpolation Calculator use?
y = y1 + (x - x1)(y2 - y1)/(x2 - x1). The slope through two points is calculated once and applied to the target x; the result is labeled interpolation when x lies within the endpoint interval.
What should I check before using the Linear Interpolation Calculator result?
The two x-values must differ. Linear interpolation assumes the relationship is adequately straight between points; extrapolation outside the interval carries more uncertainty.