Binary to decimal

Type a binary number (only 0s and 1s) and see its decimal value instantly, along with the octal and hexadecimal. Everything happens in your browser.

1101₂ = 13₁₀

🔒 What you type never leaves your device. Everything is calculated in your browser.

Type in any of the four fields and the others update on their own. No size limit, and only for positive whole numbers.

Decimal (base 10)

Binary (base 2)

Octal (base 8)

Hexadecimal (base 16)

Any base (2 to 36)

Number

From base

To base

Result

Text to binary and hex

Text

Binary (8 bits per character)You can paste bits to turn them into text.

Hexadecimal (bytes)

How to convert binary to decimal

Type the binary number in the "Binary (base 2)" field.
See the result in "Decimal (base 10)", highlighted.
You also get the octal and hexadecimal of the same number.
Tap Copy to take the results with you.

The method and an example

Each binary digit is worth a power of 2, from right to left: 1, 2, 4, 8, 16… Add up the powers wherever there is a 1. For example, 1101 = 8 + 4 + 0 + 1 = 13.

Another example: 11111111 = 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 255, the largest value that fits in 8 bits (one byte). The table below shows the first numbers in all four bases.

Decimal (base 10)	Binary (base 2)	Octal (base 8)	Hexadecimal (base 16)
0	0	0	0
1	1	1	1
2	10	2	2
3	11	3	3
4	100	4	4
5	101	5	5
6	110	6	6
7	111	7	7
8	1000	10	8
9	1001	11	9
10	1010	12	A
11	1011	13	B
12	1100	14	C
13	1101	15	D
14	1110	16	E
15	1111	17	F
16	10000	20	10
17	10001	21	11
18	10010	22	12
19	10011	23	13
20	10100	24	14
21	10101	25	15
22	10110	26	16
23	10111	27	17
24	11000	30	18
25	11001	31	19
26	11010	32	1A
27	11011	33	1B
28	11100	34	1C
29	11101	35	1D
30	11110	36	1E
31	11111	37	1F
32	100000	40	20
40	101000	50	28
50	110010	62	32
64	1000000	100	40
100	1100100	144	64
127	1111111	177	7F
128	10000000	200	80
200	11001000	310	C8
255	11111111	377	FF
256	100000000	400	100
500	111110100	764	1F4
512	1000000000	1000	200
1000	1111101000	1750	3E8
1024	10000000000	2000	400
4096	1000000000000	10000	1000
65535	1111111111111111	177777	FFFF

Good to know

Binary uses only the digits 0 and 1; any other digit shows a warning.
There is no size limit, but only positive whole numbers are converted.
Spaces and underscores are ignored, so you can paste 1111 0000.

Frequently asked questions

How do I convert 1101 from binary to decimal?

Add the powers of 2 wherever there is a 1: 8 + 4 + 1 = 13.

What is 11111111 in decimal?

255, the largest 8-bit number.

Can I convert very long binary numbers?

Yes, there is no size limit.

Is my data sent to a server?

No. The conversion happens in your browser.