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Base 21 to Base 7

Base 21 to Base 7 Converter

Enter a number in base 21 below to convert it to base 7 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 7

Base 7 works the same way: the rightmost digit counts ones, the next counts groups of 7, the next counts groups of 7×7, and so on, using 7 distinct digits.

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Quick Reference Table
Base 10 Base 21 Base 7
1 1 1
2 2 2
3 3 3
4 4 4
5 5 5
6 6 6
7 7 10
8 8 11
9 9 12
10 A 13
11 B 14
12 C 15
13 D 16
14 E 20
15 F 21
16 G 22
17 H 23
18 I 24
19 J 25
20 K 26
21 10 30
22 11 31
23 12 32
24 13 33
25 14 34
26 15 35
27 16 36
28 17 40
29 18 41
30 19 42
31 1A 43
32 1B 44
33 1C 45
34 1D 46
35 1E 50
36 1F 51
37 1G 52
38 1H 53
39 1I 54
40 1J 55
41 1K 56
42 20 60
43 21 61
44 22 62
45 23 63
46 24 64
47 25 65
48 26 66
49 27 100
50 28 101
51 29 102
52 2A 103
53 2B 104
54 2C 105
55 2D 106
56 2E 110
57 2F 111
58 2G 112
59 2H 113
60 2I 114
61 2J 115
62 2K 116
63 30 120
64 31 121
70 37 130
80 3H 143
90 46 156
100 4G 202
200 9B 404
300 E6 606
400 J1 1111
500 12H 1313
600 17C 1515
700 1C7 2020
800 1H2 2222
900 20I 2424
1000 25D 2626

View this as a standalone, printable table

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