JavaScript Number.toFixed()

toFixed(digits) formats a Number using a fixed number of digits after the decimal point and returns the result as a string.

const value = 56.879654;
console.log(value.toFixed(4)); // "56.8797"

Show Table of Contents ↓

toFixed() syntax and return value Top ↑

number.toFixed(digits)

digits controls the number of decimal places. If omitted, it defaults to 0.

Rounding to a chosen number of decimal places Top ↑

const value = 11.257;
console.log(value.toFixed(2)); // "11.26"
console.log((11.25).toFixed(1)); // "11.3"

toFixed() adds trailing zeros when needed Top ↑

console.log((11.978).toFixed(4)); // "11.9780"
console.log((5).toFixed(2));      // "5.00"

Valid digits range Top ↑

Modern JavaScript allows digits from 0 through 100. Values outside that range throw a RangeError.

try {
  console.log((3.14).toFixed(101));
} catch (error) {
  console.log(error.name); // RangeError
}

toFixed() returns a string, not a Number Top ↑

const formatted = (12.345).toFixed(2);
console.log(formatted);        // "12.35"
console.log(typeof formatted); // "string"

Using toFixed() with form or text input Top ↑

Form values are strings. Convert the input first with parseFloat() or Number(), validate it, then format it.

const amount = Number("19.9");
if (Number.isFinite(amount)) {
  console.log(amount.toFixed(2)); // "19.90"
}

Floating-point rounding can look surprising Top ↑

toFixed() formats the binary floating-point Number that JavaScript actually stores. Some decimal fractions cannot be represented exactly, so edge cases may not round as expected from the written decimal alone.

console.log((2.55).toFixed(1)); // may be "2.5" because of stored binary value

For directional rounding rules, also see Math.ceil() and Math.floor().

Use Intl.NumberFormat for user-facing currency Top ↑

toFixed(2) can produce two decimal places, but it does not add locale-aware separators or currency symbols. For currency shown to users, Intl.NumberFormat is usually the better presentation API.

const formatter = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD"
});
console.log(formatter.format(19.9));

toFixed() vs toPrecision() Top ↑

toFixed() controls digits after the decimal point. toPrecision() controls the total number of significant digits.

Related tutorials Top ↑

See parseInt(), parseFloat(), PHP number_format(), and toPrecision().

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Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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