NTILE (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
Distributes the rows in an ordered partition into a specified number of groups. The groups are numbered, starting at one. For each row, NTILE returns the number of the group to which the row belongs.
Transact-SQL syntax conventions
Syntax
NTILE (integer_expression) OVER ( [ <partition_by_clause> ] < order_by_clause > )
Arguments
integer_expression
Is a positive integer expression that specifies the number of groups into which each partition must be divided. integer_expression can be of type int, or bigint.
<partition_by_clause>
Divides the result set produced by the FROM clause into partitions to which the function is applied. For the PARTITION BY syntax, see OVER Clause (Transact-SQL).
<order_by_clause>
Determines the order in which the NTILE values are assigned to the rows in a partition. An integer cannot represent a column when the <order_by_clause> is used in a ranking function.
Return Types
bigint
Remarks
If the number of rows in a partition is not divisible by integer_expression, this will cause groups of two sizes that differ by one member. Larger groups come before smaller groups in the order specified by the OVER clause. For example if the total number of rows is 53 and the number of groups is five, the first three groups will have 11 rows and the two remaining groups will have 10 rows each. If on the other hand the total number of rows is divisible by the number of groups, the rows will be evenly distributed among the groups. For example, if the total number of rows is 50, and there are five groups, each bucket will contain 10 rows.
NTILE is nondeterministic. For more information, see Deterministic and Nondeterministic Functions.
Examples
A. Dividing rows into groups
The following example divides rows into four groups of employees based on their year-to-date sales. Because the total number of rows is not divisible by the number of groups, the first two groups have four rows and the remaining groups have three rows each.
USE AdventureWorks2022;
GO
SELECT p.FirstName, p.LastName
,NTILE(4) OVER(ORDER BY SalesYTD DESC) AS Quartile
,CONVERT(NVARCHAR(20),s.SalesYTD,1) AS SalesYTD
, a.PostalCode
FROM Sales.SalesPerson AS s
INNER JOIN Person.Person AS p
ON s.BusinessEntityID = p.BusinessEntityID
INNER JOIN Person.Address AS a
ON a.AddressID = p.BusinessEntityID
WHERE TerritoryID IS NOT NULL
AND SalesYTD <> 0;
GO
Here's the result set.
FirstName LastName Quartile SalesYTD PostalCode
------------- --------------------- --------- -------------- ----------
Linda Mitchell 1 4,251,368.55 98027
Jae Pak 1 4,116,871.23 98055
Michael Blythe 1 3,763,178.18 98027
Jillian Carson 1 3,189,418.37 98027
Ranjit Varkey Chudukatil 2 3,121,616.32 98055
José Saraiva 2 2,604,540.72 98055
Shu Ito 2 2,458,535.62 98055
Tsvi Reiter 2 2,315,185.61 98027
Rachel Valdez 3 1,827,066.71 98055
Tete Mensa-Annan 3 1,576,562.20 98055
David Campbell 3 1,573,012.94 98055
Garrett Vargas 4 1,453,719.47 98027
Lynn Tsoflias 4 1,421,810.92 98055
Pamela Ansman-Wolfe 4 1,352,577.13 98027
(14 row(s) affected)
B. Dividing the result set by using PARTITION BY
The following example adds the PARTITION BY argument to the code in example A. The rows are first partitioned by PostalCode and then divided into four groups within each PostalCode. The example also declares a variable @NTILE_Var and uses that variable to specify the value for the integer_expression parameter.
USE AdventureWorks2022;
GO
DECLARE @NTILE_Var INT = 4;
SELECT p.FirstName, p.LastName
,NTILE(@NTILE_Var) OVER(PARTITION BY PostalCode ORDER BY SalesYTD DESC) AS Quartile
,CONVERT(NVARCHAR(20),s.SalesYTD,1) AS SalesYTD
,a.PostalCode
FROM Sales.SalesPerson AS s
INNER JOIN Person.Person AS p
ON s.BusinessEntityID = p.BusinessEntityID
INNER JOIN Person.Address AS a
ON a.AddressID = p.BusinessEntityID
WHERE TerritoryID IS NOT NULL
AND SalesYTD <> 0;
GO
Here's the result set.
FirstName LastName Quartile SalesYTD PostalCode
------------ -------------------- -------- ------------ ----------
Linda Mitchell 1 4,251,368.55 98027
Michael Blythe 1 3,763,178.18 98027
Jillian Carson 2 3,189,418.37 98027
Tsvi Reiter 2 2,315,185.61 98027
Garrett Vargas 3 1,453,719.47 98027
Pamela Ansman-Wolfe 4 1,352,577.13 98027
Jae Pak 1 4,116,871.23 98055
Ranjit Varkey Chudukatil 1 3,121,616.32 98055
José Saraiva 2 2,604,540.72 98055
Shu Ito 2 2,458,535.62 98055
Rachel Valdez 3 1,827,066.71 98055
Tete Mensa-Annan 3 1,576,562.20 98055
David Campbell 4 1,573,012.94 98055
Lynn Tsoflias 4 1,421,810.92 98055
(14 row(s) affected)
Examples: Azure Synapse Analytics and Analytics Platform System (PDW)
C. Dividing rows into groups
The following example uses the NTILE function to divide a set of salespersons into four groups based on their assigned sales quota for the year 2003. Because the total number of rows is not divisible by the number of groups, the first group has five rows and the remaining groups have four rows each.
-- Uses AdventureWorks
SELECT e.LastName, NTILE(4) OVER(ORDER BY SUM(SalesAmountQuota) DESC) AS Quartile,
CONVERT (VARCHAR(13), SUM(SalesAmountQuota), 1) AS SalesQuota
FROM dbo.DimEmployee AS e
INNER JOIN dbo.FactSalesQuota AS sq
ON e.EmployeeKey = sq.EmployeeKey
WHERE sq.CalendarYear = 2003
AND SalesTerritoryKey IS NOT NULL AND SalesAmountQuota <> 0
GROUP BY e.LastName
ORDER BY Quartile, e.LastName;
Here's the result set.
LastName Quartile SalesYTD
----------------- -------- ------------`
Blythe 1 4,716,000.00
Carson 1 4,350,000.00
Mitchell 1 4,682,000.00
Pak 1 5,142,000.00
Varkey Chudukatil 1 2,940,000.00
Ito 2 2,644,000.00
Saraiva 2 2,293,000.00
Vargas 2 1,617,000.00
Ansman-Wolfe 3 1,183,000.00
Campbell 3 1,438,000.00
Mensa-Annan 3 1,481,000.00
Valdez 3 1,294,000.00
Abbas 4 172,000.00
Albert 4 651,000.00
Jiang 4 544,000.00
Tsoflias 4 867,000.00
D. Dividing the result set by using PARTITION BY
The following example adds the PARTITION BY argument to the code in example A. The rows are first partitioned by SalesTerritoryCountry and then divided into two groups within each SalesTerritoryCountry. Notice that the ORDER BY in the OVER clause orders the NTILE and the ORDER BY of the SELECT statement orders the result set.
-- Uses AdventureWorks
SELECT e.LastName, NTILE(2) OVER(PARTITION BY e.SalesTerritoryKey ORDER BY SUM(SalesAmountQuota) DESC) AS Quartile,
CONVERT (VARCHAR(13), SUM(SalesAmountQuota), 1) AS SalesQuota
,st.SalesTerritoryCountry
FROM dbo.DimEmployee AS e
INNER JOIN dbo.FactSalesQuota AS sq
ON e.EmployeeKey = sq.EmployeeKey
INNER JOIN dbo.DimSalesTerritory AS st
ON e.SalesTerritoryKey = st.SalesTerritoryKey
WHERE sq.CalendarYear = 2003
GROUP BY e.LastName,e.SalesTerritoryKey,st.SalesTerritoryCountry
ORDER BY st.SalesTerritoryCountry, Quartile;
Here's the result set.
LastName Quartile SalesYTD SalesTerritoryCountry
----------------- -------- -------------- ------------------
Tsoflias 1 867,000.00 Australia
Saraiva 1 2,293,000.00 Canada
Varkey Chudukatil 1 2,940,000.00 France
Valdez 1 1,294,000.00 Germany
Alberts 1 651,000.00 NA
Jiang 1 544,000.00 NA
Pak 1 5,142,000.00 United Kingdom
Mensa-Annan 1 1,481,000.00 United States
Campbell 1 1,438,000.00 United States
Reiter 1 2,768,000.00 United States
Blythe 1 4,716,000.00 United States
Carson 1 4,350,000.00 United States
Mitchell 1 4,682,000.00 United States
Vargas 2 1,617,000.00 Canada
Abbas 2 172,000.00 NA
Ito 2 2,644,000.00 United States
Ansman-Wolfe 2 1,183,000.00 United States
See Also
RANK (Transact-SQL)
DENSE_RANK (Transact-SQL)
ROW_NUMBER (Transact-SQL)
Ranking Functions (Transact-SQL)
Built-in Functions (Transact-SQL)