Binary, Hex and Decimal Converter

Type a number in decimal, binary, hexadecimal, octal or any base from 2 to 36 and the others update as you type, with no limit on size. Every bit is drawn with its place value and small numbers are written as a sum of powers of two. Pick a width of 8, 16, 32 or 64 bits to see negative numbers in two's complement and any value as signed and unsigned. Digits are grouped for reading, prefixes such as 0x and 0b are accepted and can be shown, and each result copies in one click.

How it works

Binary, Hex and Decimal Converter is a web page that does its work on your own device. Everything you type or choose is worked out by your browser and never sent to a server, so nothing is stored and there is nothing to delete. There is no account, no sign-up and no limit on how often you use it.

Straight to one job

Binary to Decimal Converter · Hex to Decimal Converter · Decimal to Binary Converter

One number, every base

Type a number into any box, decimal, binary, hexadecimal, octal or any base from 2 to 36, and the others fill in as you type. Numbers can be as large as you like, well past the 64-bit limit of most calculators, and are written grouped for reading: binary in fours, hex in pairs, decimal with thousands commas. Prefixes such as 0x, 0b, 0o and #, and spaces or underscores between digits, are accepted when you paste, so a value copied from code or a colour picker works straight away.

Bits you can see

Under the boxes every bit is drawn with its place, so you can see which are on, and small values are written out as a sum of powers of two: 255 = 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1. That is the quickest way to check a flag mask, a permission value, a register or a homework answer.

Negative numbers and widths

Computers store negative whole numbers in two's complement, which depends on how many bits the value has. Pick 8, 16, 32 or 64 bits and a negative decimal is written the way a processor stores it, so -1 in 8 bits is 1111 1111 and FF. Going the other way, a binary or hex value is shown both as an unsigned number and as a signed one at that width. Without a width, a negative number is simply written with a minus sign.

What this tool does not do

• It does not convert fractions; whole numbers only.
• It does not convert text to binary or hex; that is a character encoding, not a number.

What it does

• Decimal, binary, hex, octal and any base from 2 to 36
• Updates as you type, from whichever box you type in
• Numbers of any size, past 64 bits
• Every bit drawn, with powers of two for small values
• Two's complement and signed or unsigned at 8, 16, 32 or 64 bits
• Accepts 0x, 0b, 0o, # and spaces; grouping and capitals optional
• No upload, no account, no sign-up

Questions

How do I convert binary to decimal?

Type the binary number in the Binary box. Each digit is a power of two, counted from the right starting at 1: 1010 is 8 + 2 = 10. The decimal box shows the answer as you type.

How do I convert hex to decimal?

Type the hex value in the Hexadecimal box, with or without 0x or #. Each hex digit is four bits, A to F stand for 10 to 15, so FF is 15 × 16 + 15 = 255.

How do I convert decimal to binary?

Type the number in the Decimal box. The Binary box shows it, grouped in fours, and the bits are drawn below with their place values.

What is two's complement?

The way computers store negative whole numbers: at a given width, -n is stored as 2 to the power of the width minus n. In 8 bits, -1 is 1111 1111. Choose a width to see it.

How big a number can it handle?

Any size. The converter works with whole numbers of any length, so 128-bit hashes and very long decimals convert exactly.

Can I convert fractions?

No, whole numbers only. Fractions in binary rarely end, which is why 0.1 cannot be stored exactly in a computer.

What bases can it use?

Any base from 2 to 36, using the digits 0 to 9 and then the letters a to z. Base 36 is sometimes used for short codes.

Is it free?

Yes, completely free, with no sign-up.

More

Privacy policy · Support · Changelog