log10 man page

log10, log10f, log10l — base-10 logarithmic function


#include <math.h>

double log10(double x);

float log10f(float x);

long double log10l(long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

log10f(), log10l():

|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE


These functions return the base 10 logarithm of x.

Return Value

On success, these functions return the base 10 logarithm of x.

For special cases, including where x is 0, 1, negative, infinity, or NaN, see log(3).


See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

For a discussion of the errors that can occur for these functions, see log(3).


For an explanation of the terms used in this section, see attributes(7).

log10(), log10f(), log10l()Thread safetyMT-Safe

Conforming to

C99, POSIX.1-2001, POSIX.1-2008.

The variant returning double also conforms to SVr4, 4.3BSD, C89.

See Also

cbrt(3), clog10(3), exp10(3), log(3), log2(3), sqrt(3)

Referenced By

exp10(3), log(3), log2(3).

Explore man page connections for log10(3).

log10f(3) and log10l(3) are aliases of log10(3).