JavaScript Number toPrecision()

Format a number to a specified length:

let num = 13.3714;
let n = num.toPrecision(2);

Format a small number:

let num = 0.001658853;
num.toPrecision(2);
num.toPrecision(3);
num.toPrecision(10);

More examples below.

Description

The toPrecision() method formats a number to a specified length.

A decimal point and nulls are added (if needed), to create the specified length.

number.toPrecision(x)

Parameter	Description
x	Optional. The number of digits. If omitted, the number is returned without any formatting.

Type	Description
A string	The number formatted to the specified precision.

Format a number to a specified length:

let num = 13.3714;
num.toPrecision(2);
num.toPrecision(3);
num.toPrecision(10);

No formatting:

let num = 13.3714;
num.toPrecision();

toPrecision() is an ECMAScript3 (ES3) feature.

ES3 (JavaScript 1999) is fully supported in all browsers:


Chrome	Edge	Firefox	Safari	Opera	IE
Yes	Yes	Yes	Yes	Yes	Yes