The Math.log10() function returns the base 10 logarithm of a number, that is

x>0,Math.log10(x)=log10(x)=the uniqueysuch that10y=x\forall x > 0, \mathtt{\operatorname{Math.log10}(x)} = \log_10(x) = \text{the unique} \; y \; \text{such that} \; 10^y = x

Syntax

Math.log10(x)

Parameters

x
A number.

Return value

The base 10 logarithm of the given number. If the number is negative, NaN is returned.

Description

If the value of x is less than 0, the return value is always NaN.

Because log10() is a static method of Math, you always use it as Math.log10(), rather than as a method of a Math object you created (Math is not a constructor).

This function is the equivalent of Math.log(x) / Math.log(10).  For log10(e) use the constant Math.LOG10E which is 1 / Math.LN10.  

Examples

Using Math.log10()

Math.log10(2);      // 0.3010299956639812
Math.log10(1);      // 0
Math.log10(0);      // -Infinity
Math.log10(-2);     // NaN
Math.log10(100000); // 5

Polyfill

This can be emulated with the following function:

Math.log10 = Math.log10 || function(x) {
  return Math.log(x) * Math.LOG10E;
};

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Math.log10' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Math.log10' in that specification.
Draft  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support38 Yes25 No258
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes25 Yes8 Yes

See also

Document Tags and Contributors

Last updated by: wbamberg,