7 Ways To Interpolate In Excel

Interpolation is a statistical technique used to estimate values between two known points. In Excel, interpolation can be used to fill in missing data, create smooth curves, and make predictions. There are several ways to interpolate in Excel, each with its own strengths and weaknesses.

What is Interpolation in Excel?

Interpolation in Excel is a process of estimating a value within two known values in a dataset. It involves creating a mathematical model that best fits the existing data and then using that model to predict the missing value.

Method 1: Using the FORECAST Function

One of the most straightforward ways to interpolate in Excel is by using the FORECAST function. This function uses a linear regression model to estimate the missing value.

How to Use the FORECAST Function

Select the cell where you want to display the interpolated value.
Type "=FORECAST(" and select the x-value that corresponds to the missing data point.
Select the range of x-values and y-values that you want to use for the interpolation.
Press Enter to get the interpolated value.

Advantages of Using the FORECAST Function

Easy to use and understand
Fast calculation time
Can be used for both linear and non-linear interpolation

Disadvantages of Using the FORECAST Function

Limited to linear and non-linear interpolation
Not suitable for large datasets

Method 2: Using the TREND Function

Another way to interpolate in Excel is by using the TREND function. This function uses a linear or non-linear regression model to estimate the missing value.

How to Use the TREND Function

Select the cell where you want to display the interpolated value.
Type "=TREND(" and select the range of y-values that you want to use for the interpolation.
Select the range of x-values that you want to use for the interpolation.
Press Enter to get the interpolated value.

Advantages of Using the TREND Function

Can be used for both linear and non-linear interpolation
Suitable for large datasets
Fast calculation time

Disadvantages of Using the TREND Function

Not as easy to use as the FORECAST function
Limited to linear and non-linear interpolation

Method 3: Using the LINEST Function

The LINEST function is a more advanced interpolation method that uses a linear regression model to estimate the missing value.

How to Use the LINEST Function

Select the cell where you want to display the interpolated value.
Type "=LINEST(" and select the range of y-values that you want to use for the interpolation.
Select the range of x-values that you want to use for the interpolation.
Press Enter to get the interpolated value.

Advantages of Using the LINEST Function

Can be used for both linear and non-linear interpolation
Suitable for large datasets
Fast calculation time

Disadvantages of Using the LINEST Function

Not as easy to use as the FORECAST function
Limited to linear and non-linear interpolation

Method 4: Using VLOOKUP

VLOOKUP is a lookup function that can be used to interpolate values in a table.

How to Use VLOOKUP

Select the cell where you want to display the interpolated value.
Type "=VLOOKUP(" and select the value that you want to look up.
Select the range of cells that contains the data.
Select the column that contains the value that you want to interpolate.
Press Enter to get the interpolated value.

Advantages of Using VLOOKUP

Easy to use and understand
Fast calculation time
Can be used for both linear and non-linear interpolation

Disadvantages of Using VLOOKUP

Limited to linear interpolation
Not suitable for large datasets

Method 5: Using INDEX-MATCH

INDEX-MATCH is a combination of two functions that can be used to interpolate values in a table.

How to Use INDEX-MATCH

Select the cell where you want to display the interpolated value.
Type "=INDEX(" and select the range of cells that contains the data.
Type ",MATCH(" and select the value that you want to look up.
Select the range of cells that contains the data.
Press Enter to get the interpolated value.

Advantages of Using INDEX-MATCH

Easy to use and understand
Fast calculation time
Can be used for both linear and non-linear interpolation

Disadvantages of Using INDEX-MATCH

Limited to linear interpolation
Not suitable for large datasets

Method 6: Using Power Query

Power Query is a data manipulation tool that can be used to interpolate values in a table.

How to Use Power Query

Select the cell where you want to display the interpolated value.
Go to the "Data" tab and click on "From Other Sources".
Select "From Microsoft Query".
Select the table that contains the data.
Click on "Load" to load the data into Power Query.
Use the "Merge" function to merge the tables.
Use the "Fill" function to fill in the missing values.

Advantages of Using Power Query

Can be used for both linear and non-linear interpolation
Suitable for large datasets
Fast calculation time

Disadvantages of Using Power Query

Not as easy to use as other methods
Requires a good understanding of data manipulation

Method 7: Using DAX

DAX (Data Analysis Expressions) is a formula language used in Power BI and Power Pivot.

How to Use DAX

Select the cell where you want to display the interpolated value.
Go to the "Modeling" tab and click on "New Measure".
Type "=CALCULATE(" and select the measure that you want to calculate.
Use the " INTERPOLATE" function to interpolate the value.

Advantages of Using DAX

Can be used for both linear and non-linear interpolation
Suitable for large datasets
Fast calculation time

Disadvantages of Using DAX

Not as easy to use as other methods
Requires a good understanding of data analysis

Interpolation in Excel Image Gallery

We hope this article has provided you with a comprehensive guide on how to interpolate in Excel. Whether you're a beginner or an advanced user, there's an interpolation method that's right for you. Try out different methods and see which one works best for your data. Happy interpolating!