Format Number as Percent in Ms Sql Server

In SQL Server 2012 and later, there is the FORMAT() function. You can pass it a 'P' parameter for percentage. For example:

SELECT FORMAT((37.0/38.0),'P') as [Percentage] -- 97.37 %

To support percentage decimal precision, you can use P0 for no decimals (whole-numbers) or P3 for 3 decimals (97.368%).

SELECT FORMAT((37.0/38.0),'P0') as [WholeNumberPercentage] -- 97 %
SELECT FORMAT((37.0/38.0),'P3') as [ThreeDecimalsPercentage] -- 97.368 %

Using FORMAT function in new versions of SQL Server is much simpler and allows much more control:

FORMAT(yournumber, '#,##0.0%')

Benefit of this is you can control additional things like thousand separators and you don't get that space between the number and '%'.

SELECT cast( cast(round(37.0/38.0,2) AS DECIMAL(18,2)) as varchar(100)) + ' %'

RESULT:  0.97 %

And for all SQL Server versions

SELECT CAST(0.973684210526315789 * 100 AS DECIMAL(18, 2))

The issue that might rise is rounding issue.

.973684210526315789*100   -> 97.37  False
.973684210526315789*100   -> 97.36  True

there exist two approaches: String Functions and Numerical Functions

String Functions can avoid rounding issue, use functions such as CAST( equivalent CONVERT) and LEFT

SELECT LEFT(Cast(.973684210526315789*100 AS VARCHAR(100)), 5) + ' %'

SELECT LEFT(CONVERT(VARCHAR(100), .973684210526315789*100), 5) + ' %'  

Numerical Functions might bring rounding issue, to avoid it use ROUND function

SELECT LEFT(Round(.973684210526315789*100, 2, 1), 5) + ' %'  

to avoide using LEFT function(String Functions) use DECIMAL(18,2) and NUMERIC(18, 2) in cast and convert.

SELECT Concat(Cast(Round(.973684210526315789 * 100, 2, 1) AS DECIMAL(18, 2)),' %')

SELECT Concat(CONVERT(NUMERIC(10, 2), Round(.973684210526315789 * 100, 2, 1)),' %')  

in addition you can use FORMAT, ###.## and 00.00 resemble integer part and fractional part and ###.## should be preferred to 00.00 since it can avoid zero values

SELECT FORMAT(Round(.973684210526315789*100, 2, 1), '######.#####')+ ' %' ---> 97.36%

SELECT FORMAT(Round(.973684210526315789*100, 2, 1), '00000.0000')+ ' %' ---> 00097.3600% 

SELECT FORMAT(Round(.973684210526315789*100, 2, 1), '00.00')+ ' %' ---> 97.36% 

sqlfiddle

took the challenge to solve this issue. comment number 5 (M.Ali) asked for --"The required answer is 97.36 % (not 0.97 %) .." so for that i'm attaching a photo who compare between post number 3 (sqluser) to my solution. (i'm using the postgre_sql on a mac)