lanqy/bytesToSize.js

williamoliveira · 2017-01-23T00:56:55Z

ES6 and airbnb's eslint compliant version:

function bytesToSize(bytes) {
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB']
  if (bytes === 0) return 'n/a'
  const i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)), 10)
  if (i === 0) return `${bytes} ${sizes[i]})`
  return `${(bytes / (1024 ** i)).toFixed(1)} ${sizes[i]}`
}

Oluwasetemi · 2017-03-12T09:26:42Z

function bytesToSize(bytes) {
const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB']
if (bytes === 0) return 'n/a'
const i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)), 10)
if (i === 0) return ${bytes} ${sizes[i]})
return ${(bytes / (1024 ** i)).toFixed(1)} ${sizes[i]}
}

deathwebo · 2018-07-30T23:41:54Z

With little typo fixed on line 5:

function bytesToSize(bytes) {
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB']
  if (bytes === 0) return 'n/a'
  const i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)), 10)
  if (i === 0) return `${bytes} ${sizes[i]}`
  return `${(bytes / (1024 ** i)).toFixed(1)} ${sizes[i]}`
}

seahindeniz · 2018-12-24T04:47:21Z

Some may doesn't like having a seperator so:

function bytesToSize(bytes, seperator = "") {
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB']
  if (bytes == 0) return 'n/a'
  const i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)), 10)
  if (i === 0) return `${bytes}${seperator}${sizes[i]}`
  return `${(bytes / (1024 ** i)).toFixed(1)}${seperator}${sizes[i]}`
}

console.log( bytesToSize(2659633) ); // 2.5MB
console.log( bytesToSize(2659633, " ") ); // 2.5 MB
console.log( bytesToSize(2659633, "-") ); // 2.5-MB

jedfoster · 2019-01-03T20:45:07Z

I had a need to format negative values, but Math.log(x) returns NaN if x is negative, so I pass bytes through Math.abs() first.

function bytesToSize(bytes) {
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
  if (bytes === 0) return 'n/a';
  const i = parseInt(Math.floor(Math.log(Math.abs(bytes)) / Math.log(1024)), 10);
  if (i === 0) return `${bytes} ${sizes[i]}`;
  return `${(bytes / (1024 ** i)).toFixed(1)} ${sizes[i]}`;
}

console.log(bytesToSize(1234567)); // 1.2 MB
console.log(bytesToSize(-1234567)); // -1.2 MB

jzombie · 2019-10-17T01:19:26Z

@jedfoster I used your code, but just pointing out something... If you're only rendering "Bytes", there's a dangling closing parenthesis.

e.g. "Bytes)"

StasAreshin · 2020-01-13T10:49:39Z

1 redundant line removed
added suffix param
fixed error if size more then 1023 TB

function prettySize(bytes, separator = '', postFix = '') {
    if (bytes) {
        const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
        const i = Math.min(parseInt(Math.floor(Math.log(bytes) / Math.log(1024)), 10), sizes.length - 1);
        return `${(bytes / (1024 ** i)).toFixed(i ? 1 : 0)}${separator}${sizes[i]}${postFix}`;
    }
    return 'n/a';
}

Akifcan · 2020-02-03T14:10:25Z

thank you

ZachMoreno · 2020-04-04T21:40:56Z

fixed a type error on line 4, Argument of type 'number' is not assignable to parameter of type 'string'

prettySize(bytes, separator = '', postFix = '') {
    if (bytes) {
        const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
        const i = Math.min(parseInt(Math.floor(Math.log(bytes) / Math.log(1024)).toString(), 10), sizes.length - 1);
        return `${(bytes / (1024 ** i)).toFixed(i ? 1 : 0)}${separator}${sizes[i]}${postFix}`;
    }
    return 'n/a';
}

zackster · 2020-04-14T02:13:09Z

A little bit of code for people who want the reverse.
Basically adapted this from https://stackoverflow.com/a/31625253/104461

function printpower (n, base, power) {
  if (base === 2) { // 1 << power is approx 10x faster than Math.pow(2, power) 
    console.log(n * (1 << power))
  } else {
    console.log(n * Math.pow(base, power))
  }
}

const humanReadable = '86 MB'

const [n, abbreviation] = humanReadable.split(/\s+/)
if (abbreviation) {
  if (/K(iB)?$/.test(abbreviation)) {
    printpower(n, 2, 10)
  } else if (/M(iB)?$/.test(abbreviation)) {
    printpower(n, 2, 20)
  } else if (/G(iB)?$/.test(abbreviation)) {
    printpower(n, 2, 30)
  } else if (/T(iB)?$/.test(abbreviation)) {
    printpower(n, 2, 40)
  } else if (/KB$/.test(abbreviation)) {
    printpower(n, 10, 3)
  } else if (/MB$/.test(abbreviation)) {
    printpower(n, 10, 6)
  } else if (/GB$/.test(abbreviation)) {
    printpower(n, 10, 9)
  } else if (/TB$/.test(abbreviation)) {
    printpower(n, 10, 12)
  }
} else {
  console.log(n)
}

Edit: the if statement is probably pretty expensive, and so are the Regular Expressions (at a minimum, should be compiled once as const variables), so there is room for incremental optimization!

tobiasalbirosa · 2020-11-17T21:11:57Z

Thanks all of you

ahmnouira · 2021-01-12T07:27:35Z

TypeScript version:

export function bytesToSize(bytes: number): string {
  const sizes: string[] = ['Bytes', 'KB', 'MB', 'GB', 'TB']
  if (bytes === 0) return 'n/a'
  const i: number = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)).toString())
  if (i === 0) return `${bytes} ${sizes[i]}`
  return `${(bytes / Math.pow(1024, i)).toFixed(1)} ${sizes[i]}`
}

trankov · 2021-07-14T19:10:04Z

Strength and power of open source community. I'm shocked and impressed. Thanks to all, guys.

denik1981 · 2021-08-27T18:34:54Z

function bytesToSize(bytes) {
  const units = ["byte", "kilobyte", "megabyte", "terabyte", "petabyte"];
  const unit = Math.floor(Math.log(bytes) / Math.log(1024));
  return new Intl.NumberFormat("en", {style: "unit", unit: units[unit]}).format(bytes / 1024 ** unit);
}

rmorlok · 2022-07-08T17:29:06Z

To expand on the typescript version, I don't think the parseInt(...) is required. Also, in the unlikely case that you exceed 999.9 TB, you end up in xxx.x undefined territory.

Here is a fixed Typescript version:

export function bytesToSize(bytes: number): string {
  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
  if (bytes === 0) return 'n/a';
  const i = Math.min(Math.floor(Math.log(bytes) / Math.log(1024)), sizes.length - 1);
  if (i === 0) return `${bytes} ${sizes[i]}`;
  return `${(bytes / (1024 ** i)).toFixed(1)} ${sizes[i]}`;
}

With Jest spec:

describe('bytesToSize', () => {
  test.each([
    [0, 'n/a'],
    [1, '1 Bytes'],
    [2000, '2.0 KB'],
    [30000, '29.3 KB'],
    [400000, '390.6 KB'],
    [5000000, '4.8 MB'],
    [60000000, '57.2 MB'],
    [700000000, '667.6 MB'],
    [8000000000, '7.5 GB'],
    [90000000000, '83.8 GB'],
    [100000000000, '93.1 GB'],
    [1100000000000, '1.0 TB'],
    [12000000000000, '10.9 TB'],
    [130000000000000, '118.2 TB'],
    [1400000000000000, '1273.3 TB'],
    [15000000000000000, '13642.4 TB'],
  ])('.bytesToSize(%p)', (
    val: number,
    expected: string,
  ) => {
    expect(
      bytesToSize(val),
    ).toBe(expected);
  });
});

Dymerz · 2022-11-23T18:35:08Z

Using the Intl.NumberFormat for local friendly conversions

export function bytesToSize(bytes: number): string {
  const units = ['byte', 'kilobyte', 'megabyte', 'gigabyte', 'terabyte'];

  const navigatorLocal = navigator.languages && navigator.languages.length >= 0 ? navigator.languages[0] : 'en-US'
  const unitIndex      = Math.max(0, Math.min(Math.floor(Math.log(bytes) / Math.log(1024)), units.length - 1));

  return Intl.NumberFormat(navigatorLocal, {
    style: 'unit',
    unit : units[unitIndex]
  }).format(bytes / (1024 ** unitIndex))
}

HaukeHa · 2023-09-28T06:57:36Z

The sizes should be named Mebibyte (MiB), Gibibyte (GiB) etc if you use 1024 for the calculation.

Or if you want to calculate Megabyte, Gigabyte etc. replace the '1024' in the code by '1000'.

gynekolog · 2023-11-09T14:11:52Z

@HaukeHa Thank you for noticing 👍

I use the following code:

export function convertBytes(bytes: number, options: { useBinaryUnits?: boolean; decimals?: number } = {}): string {
  const { useBinaryUnits = false, decimals = 2 } = options;

  if (decimals < 0) {
    throw new Error(`Invalid decimals ${decimals}`);
  }

  const base = useBinaryUnits ? 1024 : 1000;
  const units = useBinaryUnits
    ? ["Bytes", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"]
    : ["Bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];

  const i = Math.floor(Math.log(bytes) / Math.log(base));

  return `${(bytes / Math.pow(base, i)).toFixed(decimals)} ${units[i]}`;
}

and basic tests:

import { describe, expect } from "vitest";
import { convertBytes } from "./bytes";

describe("convertBytes", () => {
  const fileSizeInBytes = 2048;

  describe("default conversion", () => {
    it("should convert to KB", () => {
      const resultKB = convertBytes(fileSizeInBytes);
      expect(resultKB).toBe("2.05 KB");
    });

    it("should convert to MB", () => {
      const resultMB = convertBytes(fileSizeInBytes * 1000);
      expect(resultMB).toBe("2.05 MB");
    });

    it("should throw an error for invalid decimals", () => {
      expect(() => convertBytes(fileSizeInBytes, { decimals: -1 })).toThrowError("Invalid decimals -1");
    });
  });

  describe("conversion to binary units", () => {
    it("should convert to KiB", () => {
      const resultKiB = convertBytes(fileSizeInBytes, { useBinaryUnits: true });
      expect(resultKiB).toBe("2.00 KiB");
    });

    it("should convert to MiB", () => {
      const resultMiB = convertBytes(fileSizeInBytes * 1024, { useBinaryUnits: true });
      expect(resultMiB).toBe("2.00 MiB");
    });
  });

  it("should handle very large bytes (Number.MAX_SAFE_INTEGER)", () => {
    const result = convertBytes(Number.MAX_SAFE_INTEGER);
    expect(result).toBe("9.01 PB");
  });
});

artembelik · 2024-03-18T11:18:06Z

  const units = ["byte", "kilobyte", "megabyte", "terabyte", "petabyte"];

you lost "gigabyte"

	// from http://scratch99.com/web-development/javascript/convert-bytes-to-mb-kb/
	function bytesToSize(bytes) {
	var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
	if (bytes == 0) return 'n/a';
	var i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)));
	if (i == 0) return bytes + ' ' + sizes[i];
	return (bytes / Math.pow(1024, i)).toFixed(1) + ' ' + sizes[i];
	};

lanqy/bytesToSize.js

williamoliveira commented Jan 23, 2017

Oluwasetemi commented Mar 12, 2017

deathwebo commented Jul 30, 2018

seahindeniz commented Dec 24, 2018 •

edited

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jedfoster commented Jan 3, 2019 •

edited

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jzombie commented Oct 17, 2019

StasAreshin commented Jan 13, 2020 •

edited

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Akifcan commented Feb 3, 2020

ZachMoreno commented Apr 4, 2020

zackster commented Apr 14, 2020 •

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tobiasalbirosa commented Nov 17, 2020

ahmnouira commented Jan 12, 2021

trankov commented Jul 14, 2021

denik1981 commented Aug 27, 2021 •

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rmorlok commented Jul 8, 2022

Dymerz commented Nov 23, 2022

HaukeHa commented Sep 28, 2023

gynekolog commented Nov 9, 2023 •

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artembelik commented Mar 18, 2024

lanqy/bytesToSize.js

williamoliveira commented Jan 23, 2017

Oluwasetemi commented Mar 12, 2017

deathwebo commented Jul 30, 2018

seahindeniz commented Dec 24, 2018 • edited Loading

jedfoster commented Jan 3, 2019 • edited Loading

jzombie commented Oct 17, 2019

StasAreshin commented Jan 13, 2020 • edited Loading

Akifcan commented Feb 3, 2020

ZachMoreno commented Apr 4, 2020

zackster commented Apr 14, 2020 • edited Loading

tobiasalbirosa commented Nov 17, 2020

ahmnouira commented Jan 12, 2021

trankov commented Jul 14, 2021

denik1981 commented Aug 27, 2021 • edited Loading

rmorlok commented Jul 8, 2022

Dymerz commented Nov 23, 2022

HaukeHa commented Sep 28, 2023

gynekolog commented Nov 9, 2023 • edited Loading

artembelik commented Mar 18, 2024

seahindeniz commented Dec 24, 2018 •

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jedfoster commented Jan 3, 2019 •

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StasAreshin commented Jan 13, 2020 •

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zackster commented Apr 14, 2020 •

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denik1981 commented Aug 27, 2021 •

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gynekolog commented Nov 9, 2023 •

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