Size: Vastu

The size of Vastu is defined by its dimensions. Anthropometric measurements are used in Vastuvidya. The basic unit is vyama, the span between the tips of middle fingers when both arms are outstretched. In a standard person this is equal to its height (Kaya). Octal subdivisions are used to define the sub-units. Is one-eighth and one-eighth vyama a pada pada is a angulation. In addition to the anthropometric measures (purusapramana) the grain size was also used to define the dimensions, as of course in the agricultural community. The width of the barley (yavodara) was used as a standard dimension and was Yava. The two systems were linked by the relationship, 8 = 1 Yava angulation. Successive octal subdivisions Yava yield Tila, LIKSA, romagra, radhadhuli and paramanu (Table 01).

1 paramanu	1 paramanu
8 paramanu	1 radhadhuli
8 radhadhuli	1 romagra
8 romagra	1 liksa
8 liksa	1 tila
8 tila	1 yava
8 yava	1 angula
8 angula	= 1 pada
8 pada	1 vyama

Table 01. Octal system of Measurement.
To account for the difference in human proportions due to ethnic differences, three types of angula are proposed:
6 yava = 1 athamangula
7 yava = 1 madhyamangula
8 yava = 1 uttamangula
Uttamngula of 8 yava is taken as the standard.
The standardised value of angula in metric system will be 3 cm. Therefore, 1 pada = 8 angula = 24 cm and 1 vyama = 64 angula = 192 cm. One yava will then be equal to 3.75 mm and one tila will be 0.47 mm. For practical use in the field a measure called hasta equal to 24 angula is defined. This is equal to the length of arm from the shoulder. Several hastas were used with measures of 25, 26, 27, 28,29, 30 and 31 angula, but the hasta of 24 angula length called kisku is universally adopted. The other hastas are used for special purposes. One half of hasta i.e. 12 angula is called vitasti and one eighth hasta = 3 angula is called parva. Hasta, vitasti and parva are practical units.
For larger measurements, a unit called danda is used. One danda is the perimeter of a square of side 1 hasta and therefore, equal to 4 hasta. Eight danda makes one rajju and 1000 rajju is one yojana.