SQL Server Data Types

Numeric data types store numbers. Choose the smallest type that can accommodate your data.

Type	Storage	Range	Example
tinyint	1 byte	0‑255	200
smallint	2 bytes	-32,768‑32,767	-1200
int	4 bytes	-2,147,483,648‑2,147,483,647	1024
bigint	8 bytes	-9,223,372,036,854,775,808‑9,223,372,036,854,775,807	1234567890123
decimal(p,s)	Varies	Exact numeric	decimal(10,2) = 12345.67
float	4 or 8 bytes	Approximate numeric	3.14159

Store text data. Use fixed‑length types when the length is consistent; otherwise use variable‑length.

Type	Storage	Max Length	Usage
char(n)	n bytes	1‑8000	Fixed length
varchar(n)	2 + actual length	1‑8000	Variable length
varchar(max)	2 + actual length	2^31‑1 bytes	Large text
nchar(n)	2n bytes	1‑4000	Unicode fixed
nvarchar(n)	2 + actual length	1‑4000	Unicode variable
nvarchar(max)	2 + actual length	2^31‑1 bytes	Unicode large text

Store temporal information with various precisions.

Type	Storage	Range	Precision
date	3 bytes	0001‑01‑01 to 9999‑12‑31	Day
datetime	8 bytes	1753‑01‑01 to 9999‑12‑31	3.33 ms
datetime2(p)	6‑8 bytes	0001‑01‑01 to 9999‑12‑31	100 ns
datetimeoffset(p)	10‑12 bytes	Same as datetime2	Time zone offset
time(p)	3‑5 bytes	00:00:00 to 23:59:59.9999999	100 ns
smalldatetime	4 bytes	1900‑01‑01 to 2079‑06‑06	Minute

Store raw binary data such as images or files.

Type	Storage	Max Length
binary(n)	n bytes	1‑8000
varbinary(n)	2 + actual length	1‑8000
varbinary(max)	2 + actual length	2^31‑1 bytes
image	Variable	2^31‑1 bytes (deprecate)

• uniqueidentifier – 16‑byte GUID.
• sql_variant – Stores values of various data types.
• xml – Stores XML data with optional schema validation.
• geography and geometry – Spatial data types.