Approximate number data types for use with floating point numeric data. Floating point data is approximate; not all values in the data type range can be precisely represented.
Syntax
float [ ( n ) ]
Is a floating point number data with the following valid values: - 1.79E + 308 through -2.23E - 308, 0 and 2.23E -308 through 1.79E + 308. n is the number of bits used to store the mantissa of the float number in scientific notation and thus dictates the precision and storage size. n must be a value from 1 through 53. The default value of n is 53.
| n is | Precision | Storage size |
| 1-24 | 7 digits | 4 bytes |
| 25-53 | 15 digits | 8 bytes |
The Microsoft® SQL Server™ float[(n)] data type conforms to the SQL-92 standard for all values of n from 1 to 53. The synonym for double precision is float(53).
real
Is a floating point number data with the following valid values: –3.40E + 38 through -1.18E - 38, 0 and 1.18E - 38 through 3.40E + 38. Storage size is 4 bytes. In SQL Server, the synonym for real is float(24).
Note Microsoft® SQL Server™ 2000 treats n as one of two possible values. If 1<=n<=24, n is treated as 24. If 25<=n<=53, n is treated as 53.
See Also
ALTER TABLE
CAST and CONVERT
CREATE TABLE
Data Type Conversion
Data Types
DECLARE @local_variable
DELETE
INSERT
SET @local_variable
UPDATE
