The SQL SQRT Function finds the square root of the specified expression or numeric number. The syntax of the SQRT Function to find the square root is
SELECT SQRT (Float_Expression) FROM [Source]
For this demo, we use the Mathematical table data

SQL Server SQRT Function Example
The SQRT Function finds the square root of a given numeric value. The following Mathematical query will show multiple ways to use this one.
We declared a float and int variable and assigned the values. Next, we used the SQL Server math function to calculate the square root of the variable @i. It means √4 = 2.
Next, we used the integer value as input for the SQRT function.
It means, SQRT(@j) = √2.20 = 1.483. But we are getting 1.4142 as a result because it is rounding the 2.20 value to 2, and the square root of 2 is 1.4142
DECLARE @i float = 4, @j int = 2.20 SELECT SQRT(@i) AS [SQLSQRT] -- Calculating directly SELECT SQRT(9.90) AS [SQLSQRT] -- Wrong Value SELECT SQRT(@j) AS [SQLSQRT] SELECT SQRT(2.20) AS [SQLSQRT]

NOTE: Please use float variables as an input for SQRT Function. Otherwise, you may expect strange results.
Example 2
The SQRT Function also allows you to find the square root of column values. Here, We will calculate the square of All the records present in [Sales Amount] using it.
SELECT [EnglishProductName] ,[Color] ,[StandardCost] ,[SalesAmount] ,SQRT([SalesAmount]) AS Sales FROM [Mathemetical Functions]
