int, bigint, smallint, and tinyint

Only tiny int can not store negative values

Exact-number data types that use integer data. To save space in the database, use the smallest data type that can reliably contain all possible values. For example, tinyint would be sufficient for a persons age, because no one lives to be more than 255 years old. But tinyint would not be sufficient for a buildings age, because a building can be more than 255 years old.

Data type	Range	Storage
bigint	-2^63 (-9,223,372,036,854,775,808) to 2^63-1 (9,223,372,036,854,775,807)	8 Bytes
int	-2^31 (-2,147,483,648) to 2^31-1 (2,147,483,647)	4 Bytes
smallint	-2^15 (-32,768) to 2^15-1 (32,767)	2 Bytes
tinyint	0 to 255	1 Byte

Remarks

The int data type is the primary integer data type in SQL Server. The bigint data type is intended for use when integer values might exceed the range that is supported by the int data type.

bigint fits between smallmoney and int in the data type precedence chart.

Functions return bigint only if the parameter expression is a bigint data type. SQL Server does not automatically promote other integer data types (tinyint, smallint, and int) to bigint.