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Base 21 to Base 9

Base 21 to Base 9 Converter

Enter a number in base 21 below to convert it to base 9 instantly.

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About These Bases

Base 21

In base 21, each digit position represents a power of 21: the rightmost digit counts individual ones, the next counts groups of 21, the next counts groups of 21×21, and so on — the same place-value idea as base 10, just with 21 distinct digits instead of ten.

Base 9

Base 9 works the same way: the rightmost digit counts ones, the next counts groups of 9, the next counts groups of 9×9, and so on, using 9 distinct digits.

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Quick Reference Table
Base 10 Base 21 Base 9
1 1 1
2 2 2
3 3 3
4 4 4
5 5 5
6 6 6
7 7 7
8 8 8
9 9 10
10 A 11
11 B 12
12 C 13
13 D 14
14 E 15
15 F 16
16 G 17
17 H 18
18 I 20
19 J 21
20 K 22
21 10 23
22 11 24
23 12 25
24 13 26
25 14 27
26 15 28
27 16 30
28 17 31
29 18 32
30 19 33
31 1A 34
32 1B 35
33 1C 36
34 1D 37
35 1E 38
36 1F 40
37 1G 41
38 1H 42
39 1I 43
40 1J 44
41 1K 45
42 20 46
43 21 47
44 22 48
45 23 50
46 24 51
47 25 52
48 26 53
49 27 54
50 28 55
51 29 56
52 2A 57
53 2B 58
54 2C 60
55 2D 61
56 2E 62
57 2F 63
58 2G 64
59 2H 65
60 2I 66
61 2J 67
62 2K 68
63 30 70
64 31 71
70 37 77
80 3H 88
90 46 110
100 4G 121
200 9B 242
300 E6 363
400 J1 484
500 12H 615
600 17C 736
700 1C7 857
800 1H2 1078
900 20I 1210
1000 25D 1331

View this as a standalone, printable table

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