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Interpolation Calculator Online: Easily Compute Interpolated Values

Accurate & Quick Interpolation Results at Your Fingertips

How Can You Calculate Interpolation with an Interpolation Calculator?

An interpolation calculator simplifies the process of determining an interpolated rate or value between two known points. When using an interpolation calculator, you typically need to input at least three pieces of data: two pairs of coordinates, (𝑋1,𝑌1)(X1​,Y1​) and (𝑋3,𝑌3)(X3​,Y3​), which define the ends of the line segment, and an 𝑋2X2​ value for which you want to find the corresponding 𝑌2Y2​ value.


The calculator uses the linear interpolation formula: 𝑌2=𝑌1+{(𝑋2−𝑋1)(𝑌3−𝑌1)}/(𝑋3−𝑋1)

This formula helps determine the value of Y2​ based on your inputs, showing how 𝑌Y values change with 𝑋X within the range of data.

How Do You Use Excel and Google Sheets for Calculating Interpolation?

In Excel and Google Sheets, interpolation can be computed using a similar approach, although it requires a bit more manual setup compared to using a dedicated interpolation calculator:

  1. Excel:

    • Input your known data points in two columns, for example, 𝐴1:𝐴3A1:A3 for 𝑋X values and 𝐵1:𝐵3B1:B3 for 𝑌Y values.

    • Suppose you want to interpolate to find 𝑌Y for an 𝑋X value at cell 𝐴4A4. You can use the FORECAST.LINEAR function:

      =FORECAST.LINEAR(A4, B1:B3, A1:A3)

    • This function predicts a future value along a line of best fit based on the linear relationship established by the data points.

  2. Google Sheets:

    • The process is similar to Excel. Use the same function:

      =FORECAST.LINEAR(A4, B1:B3, A1:A3)

    • Ensure your data is appropriately placed in the columns, and simply input the formula in the cell where you want the interpolated result to appear.

Check out - the 5 Number Summary Calculator.

What Exactly Is an Interpolated Rate?

The term "interpolated rate" typically refers to a value derived between two known values over a continuum, based on the assumption that the change between these values is linear. It is commonly used in statistics, finance, and various types of data analysis where estimating values within two endpoints is necessary. The interpolated rate provides a critical estimation that can help in making decisions based on trends extrapolated from existing data points.

Another Useful tool - RREF Calculator.

How Is Interpolation Calculated?

Interpolation, particularly linear interpolation, is calculated by identifying two known points on a graph or within a dataset and assuming a straight line between these points. The interpolated value is then calculated for a given 𝑋X value that lies between the two known 𝑋X coordinates. The basic formula used (as mentioned above) is straightforward and can be applied manually, with a calculator specifically designed for interpolation, or through spreadsheet tools like Excel and Google Sheets.

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