C log10()

The log10() function defined in the math.h header file. It helps to return the base 10 logarithm of the given argument value.

double log10(double x); #where x should be in double

Also, two functions log10f() and log10l() were used with type float and long double respectively.

float log10f(float x); 
long double log10l(long double x); 

log10() Parameters:

The log10() function takes a single parameter in double.

Parameter Description Required / Optional
x whose base 10 logarithm needs to be found Required

log10() Return Value

The return value of log() function is a number in float.

Input Return Value
x > 0 Finds the log10 of the argument
x < 0 Shows run-time error

Examples of log10()

Example 1: Working of log10() function in C?

#include <stdio.h>
#include <math.h>
int main()
    double N = 4.00, output;

    output = log10(N);
    printf("The value of log10(%.1f) is %.2f", N, output);

    return 0;


The value of log10(4.0) is 0.60

Example 2: How log10() function worked in C?

#include <stdio.h>
#include <math.h>
int main () {
   double k, out;
   k = 10000;
   out = log10(k);
   printf("The value of log10(%lf) is %lf", k, out);



The value of log10(10000.000000) = 4.000000