10進数の文字数と、16進数の文字数の比較表です。
（末尾に 'L' や 'LL' が付く場合は考慮していません）
1012 (13文字)から16進数の方が短め
1017 (18文字)から16進数の方が短い
| 10進数 | 16進数 | |||
|---|---|---|---|---|
0 |
1 | < | 3 | 0x0 |
9 |
1 | < | 3 | 0x9 |
10 |
2 | < | 3 | 0xa |
15 |
2 | < | 3 | 0xf |
16 |
2 | < | 4 | 0x10 |
99 |
2 | < | 4 | 0x63 |
100 |
3 | < | 4 | 0x64 |
255 |
3 | < | 4 | 0xff |
256 |
3 | < | 5 | 0x100 |
999 |
3 | < | 5 | 0x3e7 |
1000 |
4 | < | 5 | 0x3e8 |
4095 |
4 | < | 5 | 0xfff |
4096 |
4 | < | 6 | 0x1000 |
9999 |
4 | < | 6 | 0x270f |
10000 |
5 | < | 6 | 0x2710 |
65535 |
5 | < | 6 | 0xffff |
65536 |
5 | < | 7 | 0x10000 |
99999 |
5 | < | 7 | 0x1869f |
100000 |
6 | < | 7 | 0x186a0 |
999999 |
6 | < | 7 | 0xf423f |
1000000 |
7 | = | 7 | 0xf4240 |
1048575 |
7 | = | 7 | 0xfffff |
1048576 |
7 | < | 8 | 0x100000 |
9999999 |
7 | < | 8 | 0x98967f |
10000000 |
8 | = | 8 | 0x989680 |
16777215 |
8 | = | 8 | 0xffffff |
16777216 |
8 | < | 9 | 0x1000000 |
99999999 |
8 | < | 9 | 0x5f5e0ff |
100000000 |
9 | = | 9 | 0x5f5e100 |
268435455 |
9 | = | 9 | 0xfffffff |
268435456 |
9 | < | 10 | 0x10000000 |
999999999 |
9 | < | 10 | 0x3b9ac9ff |
1000000000 |
10 | = | 10 | 0x3b9aca00 |
4294967295 |
10 | = | 10 | 0xffffffff |
4294967296 |
10 | < | 11 | 0x100000000 |
9999999999 |
10 | < | 11 | 0x2540be3ff |
10000000000 |
11 | = | 11 | 0x2540be400 |
68719476735 |
11 | = | 11 | 0xfffffffff |
68719476736 |
11 | < | 12 | 0x1000000000 |
99999999999 |
11 | < | 12 | 0x174876e7ff |
100000000000 |
12 | = | 12 | 0x174876e800 |
999999999999 |
12 | = | 12 | 0xe8d4a50fff |
1000000000000 |
13 | > | 12 | 0xe8d4a51000 |
1099511627775 |
13 | > | 12 | 0xffffffffff |
1099511627776 |
13 | = | 13 | 0x10000000000 |
9999999999999 |
13 | = | 13 | 0x9184e729fff |
10000000000000 |
14 | > | 13 | 0x9184e72a000 |
17592186044415 |
14 | > | 13 | 0xfffffffffff |
17592186044416 |
14 | = | 14 | 0x100000000000 |
99999999999999 |
14 | = | 14 | 0x5af3107a3fff |
100000000000000 |
15 | > | 14 | 0x5af3107a4000 |
281474976710655 |
15 | > | 14 | 0xffffffffffff |
281474976710656 |
15 | = | 15 | 0x1000000000000 |
999999999999999 |
15 | = | 15 | 0x38d7ea4c67fff |
1000000000000000 |
16 | > | 15 | 0x38d7ea4c68000 |
4503599627370495 |
16 | > | 15 | 0xfffffffffffff |
4503599627370496 |
16 | = | 16 | 0x10000000000000 |
9999999999999999 |
16 | = | 16 | 0x2386f26fc0ffff |
10000000000000000 |
17 | > | 16 | 0x2386f26fc10000 |
72057594037927935 |
17 | > | 16 | 0xffffffffffffff |
72057594037927936 |
17 | = | 17 | 0x100000000000000 |
99999999999999999 |
17 | = | 17 | 0x16345785d89ffff |
100000000000000000 |
18 | > | 17 | 0x16345785d8a0000 |
999999999999999999 |
18 | > | 17 | 0xde0b6b3a763ffff |
1000000000000000000 |
19 | > | 17 | 0xde0b6b3a7640000 |
1152921504606846975 |
19 | > | 17 | 0xfffffffffffffff |
1152921504606846976 |
19 | > | 18 | 0x1000000000000000 |
9999999999999999999 |
19 | > | 18 | 0x8ac7230489e7ffff |
10000000000000000000 |
20 | > | 18 | 0x8ac7230489e80000 |
18446744073709551615 |
20 | > | 18 | 0xffffffffffffffff |