A long integer is a term used in computer programming to describe a variable that can hold a positive or negative number, whose range is greater or equal to that of a standard integer on the same machine.

In practice it is usual for a long integer to require double the storage capacity of a standard integer, and consequently hold double the number of discreet values, although this is not always the case.

A variable defined as a long integer in one programming language may be different in size to a similarly defined variable in another. In some languages this size is fixed, whilst in others it is machine dependant. In some languages the type does not exist at all.