# float and real (Transact-SQL)

Approximate-number data types for use with floating point numeric data. Floating point data is approximate; therefore, not all values in the data type range can be represented exactly.

Note

The ISO synonym for real is float(24).

Data type |
Range |
Storage |
---|---|---|

float |
- 1.79E+308 to -2.23E-308, 0 and 2.23E-308 to 1.79E+308 |
Depends on the value of n |

real |
- 3.40E + 38 to -1.18E - 38, 0 and 1.18E - 38 to 3.40E + 38 |
4 Bytes |

## Syntax

**float**[**(**]**n**)

Where n is the number of bits that are used to store the mantissa of the float number in scientific notation and, therefore, dictates the precision and storage size. If n is specified, it must be a value between**1**and**53**. The default value of n is**53**.nvalue

Precision

Storage size

**1-24**7 digits

4 bytes

**25-53**15 digits

8 bytes

Note

SQL Server 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**.

The SQL ServerĀ float[(n)] data type complies with the ISO standard for all values of n from **1** through **53**. The synonym for double precision is float(53).

## See Also