Strangely enough, nobody pointed out how to calculate how many bytes is taking one Unicode char. Here is the rule for UTF-8 encoded strings:
Binary Hex Comments
0xxxxxxx 0x00..0x7F Only byte of a 1-byte character encoding
10xxxxxx 0x80..0xBF Continuation byte: one of 1-3 bytes following the first
110xxxxx 0xC0..0xDF First byte of a 2-byte character encoding
1110xxxx 0xE0..0xEF First byte of a 3-byte character encoding
11110xxx 0xF0..0xF7 First byte of a 4-byte character encoding
So the quick answer is: it takes 1 to 4 bytes, depending on the first one which will indicate how many bytes it’ll take up.