It is always a good exercise to know the girls age. So, noting some specific years and animal years will be able to help you figure out their ages. Here's a little tip, girls may lie about their age or their year of birth, but they very seldom lie about the animal year they were born in (as it would be a bit too difficult to figure that out mentally), so you could use that as an indicator to their year of birth.

For example, if a girl said that she was 25, and when you queried her about her animal year, and she tells you that she was born in the year of the Snake. You could then deduce that she is born in 1977 or 31 years of age, of course if she looks a lot younger than 25, then she is actually 19 years old.

Year	Thai year	Animal year	Age
1960	2503	Rat	48
1961	2504	Ox	47
1962	2505	Tiger	46
1963	2506	Rabbit	45
1964	2507	Dragon	44
1965	2508	Snake	43
1966	2509	Horse	42
1967	2510	Goat	41
1968	2511	Monkey	40
1969	2512	Rooster	39
1970	2513	Dog	38
1971	2514	Pig	37
1972	2515	Rat	36
1973	2516	Ox	35
1974	2517	Tiger	34
1975	2518	Rabbit	33
1976	2519	Dragon	32
1977	2520	Snake	31
1978	2521	Horse	30
1979	2522	Goat	29
1980	2523	Monkey	28
1981	2524	Rooster	27
1982	2525	Dog	26
1983	2526	Pig	25
1984	2527	Rat	24
1985	2528	Ox	23
1986	2529	Tiger	22
1987	2530	Rabbit	21
1988	2531	Dragon	20
1989	2532	Snake	19
1990	2533	Horse	18
1991	2534	Goat	17