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Base 7 to Base 21

Base 7 to Base 21 Converter

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

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About These Bases

Base 7

In base 7, each digit position represents a power of 7: the rightmost digit counts individual ones, the next counts groups of 7, the next counts groups of 7×7, and so on — the same place-value idea as base 10, just with 7 distinct digits instead of ten.

Base 21

Base 21 works the same way: the rightmost digit counts ones, the next counts groups of 21, the next counts groups of 21×21, and so on, using 21 distinct digits.

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

View this as a standalone, printable table

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