Number Converter

Convert numeric values from one base (radix) to another. For example, the decimal value 100 becomes Bk in Base64 (text strings are not encoded). Values over 64 bits may lose precision. Encoding happens locally, so private data is not sent to the server.

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▶ Numeric Alphabet Reference Click to Expand

Numeric Alphabet Reference

Base Name Standard Alphabet
1 Unary Traditional 1
2 Binary Traditional 01
8 Octal Traditional 01234567
10 Decimal Traditional 0123456789
16 Hexadecimal Traditional 0123456789ABCDEF
16 Base16 Readable A. Bjornson 37CDFJKMPQRTVXYZ
25 Open Postcode Open Postcode Ireland 23456789CDFGHJKLMNPQRTVWX
26 Base26 Alpha Traditional ABCDEFGHIJKLMNOPQRSTUVWXYZ
26 Bijective 26 Traditional A to Z, AA to AZ, BA to BZ, etc.
(ala Microsoft Excel)
30 Natural Area Code X. Shen 0123456789BCDFGHJKLMNPQRSTVWXZ
32 Base32 RFC 4648 ABCDEFGHIJKLMNOPQRSTUVWXYZ234567
32 Base32 Hex RFC 4648 0123456789ABCDEFGHIJKLMNOPQRSTUV
32 Base32 Crockford D. Crockford 0123456789ABCDEFGHJKMNPQRSTVWXYZ
32 ZBase32 P. Zimmermann ybndrfg8ejkmcpqxot1uwisza345h769
32 Base32 Consonants Nintendo 0123456789BCDFGHJKLMNPQRSTVWXYZ!
36 Alphadecimal 36 Traditional 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ
36 Geohash 36 Open Postcode Ireland 23456789bBCdDFgGhHjJKlLMnNPqQrRtTVWX
52 Base52 Alpha Traditional ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
58 Base58 Bitcoin S. Nakamoto 123456789ABCDEFGHJKLMNPQRSTUVWXYZ
abcdefghijkmnopqrstuvwxyz
58 Base58 Flickr S. Butterfield 123456789abcdefghijkmnopqrstuvwxyz
ABCDEFGHJKLMNPQRSTUVWXYZ
58 Base58 Ripple R. Fugger rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ
2bcdeCg65jkm8oFqi1tuvAxyz
62 Alphadecimal 62 J. Canty 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ
abcdefghijklmnopqrstuvwxyz
64 Base64 RFC 4648 ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef
ghijklmnopqrstuvwxyz0123456789+/
64 Base64 Hex RFC 4648 0123456789ABCDEFGHIJKLMNOPQRSTUV
WXYZabcdefghijklmnopqrstuvwxyz+/
64 Base64 URL RFC 4648 ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef
ghijklmnopqrstuvwxyz0123456789-_
64 BinHex P. Lewis !"#$%&'()*+,-012345689@ABCDEFGHI
JKLMNPQRSTUVXYZ[`abcdefhijklmpqr
72 Base72 Nonstandard 0123456789ABCDEFGHIJKLMNOPQRSTUV
WXYZabcdefghijklmnopqrstuvwxyz!"
#$%&'()*
85 Base85 IPv6 RFC 1924 0123456789ABCDEFGHIJKLMNOPQRSTUV
WXYZabcdefghijklmnopqrstuvwxyz!#
$%&()*+-;<=>?@^_`{|}~
85 Base85 Hex Nonstandard 0123456789ABCDEFGHIJKLMNOPQRSTUV
WXYZabcdefghijklmnopqrstuvwxyz!"
#$%&'()*+,-./:;<=>?@[
85 Ascii85 Adobe !"#$%&'()*+,-./0123456789:;<=>?@
$%&()*+-;<=>?@^_`{|}~
85 Z85 P. Hintjens 0123456789abcdefghijklmnopqrstuv
wxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$%
.-:+=^!/*?&<>()[]{}@%$#
91 Base91 J. Henke ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef
ghijklmnopqrstuvwxyz0123456789!#
$&%()*+,./:;<=>?@[]^_`{|}~"
94 Base94 Nonstandard 0123456789ABCDEFGHIJKLMNOPQRSTUV
WXYZabcdefghijklmnopqrstuvwxyz!"
#$%&'()*+,-./:;<=>?@[\\]^_`{|}~
XX Roman Numeral Traditional I 1, V 5, X 10, L 50, C 100, D 500, M 1000, etc.


▶ Common Numeric Bases Click to Expand

Common Numeric Bases

Base Name Possible Values by Digits
(1 to N)		 Binary Size
(vs. Base 256; Digits:Bytes)
1 Unary 1, 2, 3, 4 256x (256:1)
2 Binary 2, 4, 8, 16 8.00x (8:1)
8 Octal 8, 64, 512, 4096 3.00x (3:1)
10 Decimal 10, 100, 1000, 10000 ~ 3x (3:1)
16 Hexadecimal 16, 256, 4096, 65536 2.00x (2:1)
32 Base32 32, 1024, 32768, 1048576 1.60x (8:5)
36 Alphadecimal 36, 1296, 46656, 1679616 ~ 1.60x (8:5)
64 Base64 64, 4096, 262144, 16777216 1.33x (4:3)
72 Base72 72, 5184, 373248, 26873856 ~ 1.33x (4:3)
85 Base85 85, 7225, 614125, 52200625 1.25x (5:4)
91 Base91 91, 8281, 753571, 68574961 1.23x
128 US-ASCII 128, 16384, 2097152, 268435456 1.50x (3:2)
256 Extended ASCII 256, 65536, 16777216, 4294967296 1.00x (1:1)

Binary size is approximate. When used to represent binary data, some numeric bases may incur additional overhead versus the standard 8-bit representation, due to padding. Base64 digits are 6 bits, since 26 = 64. 6 bits are used out of the standard 8, so Base64 has a 1/3rd extra overhead compared to binary (6/8 = 3/4 = 1:1.3...). Various encoding cases require line breaks and/or leading/trailing characters, which aren't included in this calculation.