# DOUBLE PRECISION

Statement: Specifies the DOUBLE PRECISION data type.

DOUBLE PRECISION

A REAL(8) or DOUBLE PRECISION constant has more than twice the accuracy of a REAL(4) number, and greater range.

A REAL(8) or DOUBLE PRECISION constant occupies eight bytes of memory. The number of digits that precede the exponent is unlimited, but typically only the leftmost 15 digits are significant.

IEEE* binary64 format is used.

For more information, see General Rules for Real Constants.

## Example

    DOUBLE PRECISION varnam
    DOUBLE PRECISION,PRIVATE :: zz

Valid REAL(8) or DOUBLE PRECISION constants
123456789D+5
123456789E+5_8
+2.7843D00
-.522D-12
2E200_8
2.3_8
3.4E7_8

Invalid REAL(8) or DOUBLE PRECISION constants
-.25D0_2 | 2 is not a valid kind type for reals.
+2.7182812846182 | No D exponent designator is present; this is a valid single-precision constant.
123456789.D400 | Too large for any double-precision format.
123456789.D-400 | Too small for any double-precision format.

Parent topic: C to D

## See Also

REAL Statement
REAL(8) or DOUBLE PRECISION Constants
Data Types, Constants, and Variables
Real Data Types