Rounding Up in TSQL

The SQL ROUNDUP Options

Rounding numbers is a common task in SQL Server, and understanding how to round up specifically can be crucial for various applications, such as financial calculations or setting minimum thresholds. In this blog post, we’ll explore different methods to round up numbers in T-SQL.

The `CEILING` Function

The simplest and most direct way to round up a number in T-SQL is to use the CEILING function. This function returns the smallest integer greater than or equal to the specified numeric expression.

Syntax

CEILING ( numeric_expression )

Example

SELECT CEILING(4.2) AS RoundedUpValue;  
-- Result: 5
SELECT CEILING(-4.2) AS RoundedUpValue; 
-- Result: -4

The CEILING function works straightforwardly with both positive and negative numbers. For positive numbers, it rounds up to the next whole number. For negative numbers, it rounds up towards zero.

Rounding Up to a Specific Decimal Place

Sometimes you need to round up to a specific number of decimal places rather than the nearest whole number. While T-SQL does not have a built-in function for this, you can achieve it with a combination of CEILING and arithmetic operations.

Example: Round Up to Two Decimal Places

DECLARE @Number DECIMAL(10, 4) = 123.4567;
SELECT CEILING(@Number * 100) / 100.0 AS RoundedUpValue; 
-- Result: 123.46

Here’s how it works:

Multiply the number by 100 to shift the decimal point two places to the right.
Use the CEILING function to round up to the nearest whole number.
Divide by 100.0 to shift the decimal point back to its original position.

Rounding Up to the Nearest Multiple

In some scenarios, you might need to round up to the nearest multiple of a specific number. This can be done using a combination of the CEILING function and basic arithmetic.

Example: Round Up to the Nearest Multiple of 5

DECLARE @Number INT = 42;
SELECT CEILING(@Number / 5.0) * 5 AS RoundedUpValue;  
-- Result: 45

Explanation:

Divide the number by the desired multiple (5 in this case).
Use the CEILING function to round up to the nearest whole number.
Multiply back by the desired multiple to get the rounded value.

Handling Different Data Types

The CEILING function works with various numeric data types in SQL Server, including INT, FLOAT, DECIMAL, and NUMERIC. However, it’s essential to ensure that your expressions are compatible with the data type you’re working with to avoid unexpected results or errors.

Example with `FLOAT`

DECLARE @Number FLOAT = 123.4567;
SELECT CEILING(@Number) AS RoundedUpValue; 
 -- Result: 124

Example with `DECIMAL`

DECLARE @Number DECIMAL(10, 4) = 123.4567;
SELECT CEILING(@Number) AS RoundedUpValue; 
 -- Result: 124

Rounding up numbers in T-SQL can be efficiently accomplished using the CEILING function. Whether you need to round up to the nearest whole number, to a specific decimal place, or to the nearest multiple of a given number, combining CEILING with arithmetic operations provides a flexible solution.

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Happy Querying!

Steve Stedman
Stedman Solutions, LLC