After the Selection of Site, it is advisable to apply Vastu principles to the design of the building. This will ensure a proportionate, aesthetic and beautiful building with the right measurements. The Vastu principle ‘Aayadi – dimensions’ prescribes six formulae to work out the right dimensions (length, breadth and height) of a building.

In Vastu Shastra, formulae called Aayadi are used to work out the length, breadth, height, perimeter of buildings


Though the science of Vastu follows generic rules for the design of spaces, a specific set of six formulae called Aayadi are used to work out the Length, Breadth, perimeter, area and the height of the building. Here, the length and breadth mean the outer measurements of the foundation seen above the ground. The height of the building is considered to be from the bottom of the base to the topmost point of the building. Like the other Vaastu principles, it was necessary that one follows the Aayadi formulae strictly in order to experience positive effects within the building. In fact even today, Aayadi is the only aspect of Vaastu Shastra that is followed in many parts of India.


Aayadi constitutes six formulae Aaya, Vyaya, Yoni, Raksha, Vara and Tithi which are explained below. The remainder obtained by using these formulae determines whether it is a gain or loss. If it is a gain, then the structure is proportionate and stable and the dimensions are right. However if it is a loss, then  it means the dimensions are not right and should be suitably corrected.

  1. Yoni is the remainder of  Breadth x 3 divided by 8
  2. Vyaaya is the remainder of  Breadth x 9 divided by 10
  3. Aaya is the remainder of  Length x 8 divided by 12
  4. Raksha is the remainder of  Length x 8 divided by 27
  5. Vara is the remainder of  Height x 9 divided by 7
  6. Tithi is the remainder of  Height x 9 divided by 30
kerala house

The Aayadi formulae is used to check whether the length, breadth and height of a proposed building are in proportion


One can use the Aayadi formulae to check whether the length, breadth and height of the proposed building are in proportion. Accordingly, the dimensions of the length, breadth or height can be corrected.

BREADTH: The Yoni and Vyaya formulae are used for fixing the breadth of the building. If the  remainder obtained in the Yoni formula is an odd number, then it is good whereas if it is even, then it is considered bad Yoni. 1, 3, 5 and 7 remainders are considered good Yoni and associated with the directions East, South, West and North, respectively. Therefore depending on the direction the building faces, the corresponding Yoni should be used to fix the breadth of the building/rooms. Also, the Yoni of the first floor should  be the same as the Yoni of the ground floor. When an old house is being renovated, then a new Yoni different from the Yoni of the old house should be used for the renovated house.

LENGTH: Aaya, Vyaya and Raksha formuale are used to fix the Length of the building/rooms. Aaya also known as ‘Aadhayam’, means income and ‘Vyaya’ means loss or expenditure. Therefore, the Aaya should always be greater than the Vyaya.  Using the Aayadi formulae it has been concluded that for the Aaya to be more than the Vyaya the length of rooms/building should preferrably be 1.5 times the breadth or at least 1.375 times the width. This is why we find that sites are generally not square but rectangular with a Length 1.375  – 1.5 times the Breadth. For example: Sites have dimensions of 40 x 60, 30 x 40 and 50 x 80.

ORIENTATION: The Yoni formula defining the breadth measurement is useful for buildings that are not oriented to the cardinal directions. Vastu Shastra clearly emphasizes the importance of orienting the buildings to the four cardinal directions (North, East, South or West). As far as possible, buildings should not be oriented to the intermediate directions. But in rare situations, if the site faces an intermediate direction, the 1 Yoni should be used for fixing the breadth of the building.

The Scientific Reasoning- The ancients were aware of the power of monsoon winds and other energies (physical and metaphysical) on structures. Scientifically, it was seen that if the 4 faces of the buildings were oriented towards the cardinal directions, they could withstand the impact of these energies and also benefit from them. In fact most religious buildings, palaces, cities, villages and roads of ancient India and many other parts of the world have been found to face the cardinal directions. Examples: the Giza and Great pyramids of Egypt are all oriented to the North. So if it was  not possible to orient a building to the cardinal directions, it was important that the dimensions of the building should be such that it can withstand the forces of nature. This is where the Yoni (Breadth) calculation was useful.

HEIGHT: The height of the building can be fixed using the Vara and Tithi formulae. The height of the first floor should not be more than that of the Ground floor. For arriving at the right height of a building, the ‘Proportion’ should also be considered. This has already been explained in the post VASTU PRINCIPLE | MAANA – PROPORTION.


The height of the first floor should not be more than that of the Ground floor.


The Scientific Explanation: One reason was  that, in those days the units of measurement were not uniform in different regions. The units of measurement were Angula (3/4 of an inch) and Hasta ( 18 inches) so that 1 Hasta equals 24 Angulas. However the value of Hasta and Angula were different in different regions. Therefore, by using the Aayadi formulae for fixing the dimensions of a building, the risk of creating disproportionate spaces was eliminated.

Another reason was that these formulae were formulated in order to make it easy for the Architect to create rooms with the right sizes for the correct fit of tiles on roof purlins and roof purlins on rafters and rafters on the walls of the rooms, since in olden days, most houses had tiled roofs with wooden rafters and  purlins.


The formulae were formulated to ensure rooms with the right sizes for the correct fit of tiles on roof purlins and roof purlins on rafters and rafters on the walls of the rooms,

Typically in any wooden roof construction, the inclined roof rafters rest on the lintels/walls/under-purlins and are typically spaced at 18″ or 24″ centre to center or closer. Horizontal roof-purlins are placed on top of the rafters,to which both the top roof tiles and the decorative ceiling tiles are fixed.  Since the whole roof system is visible from the inside of the house, care is taken to have neat joints and decorative rafters, purlins and ceiling tiles. So for such precision work it was ideal that the room dimensions be in multiples of the rafter /purlin/tile spacing.

This post about the ‘Vastu Shastra principle | Aayadi – Dimensions‘, explains the six formulae used for fixing the dimensions of  a building. The dimensions, Length x Breadth x Height, are related to the form/shape of the building. Read about the different forms of buildings in the post, “Vastu Shastra principle | Chanda – Aesthetics”, here:

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  1. Anish says:

    how to calculate the pereferable height for a home L = 1751cm & W = 1525 cm

  2. jayan panackal says:

    In the ayadhi the calculation of yoni aaya and vyaya is clear but the rest is not given properly can you give an illustration for the same.


  3. Vijay says:

    What is the method to arrive the remainders of length and breadth resply?

  4. s ramamurthy says:

    we planned to construct company we planned to 30 feet X 100 feet by asbestos sheetplease guide me what will be height lenght and breath

  5. Suresh says:


    We are constructing one house.Hw to consider the vasthu width and lenght?we saw the vasthu size in website in

    feet.should we consider full building size or only room sizes as per vasthu sizes.what about it included in the vasthu size?we are under assumption that over all building size (without portico) should be as per vasthu it correct?our overall building length comes to roughly 50 feet.but no good points for this size.otherwise if we consider only room size for vasthu, we can fix our Hall room size at 33 then good points on this size.
    pls advise me.vasthu will be considered for room wise or full building wise?

    Thanks in advance.


  6. jatinder says:

    hi what should be the bed room size length and breadth according to vastu

  7. ramesh babu says:

    The measurement of North to south is 13 sq feet and the measurement of East to west is 15 sq feet .pl tell me the result is it good or Bad.

  8. pradeep.mannil says:

    one example :for calculating yoni , same example can be used for other ayyadi calculations too.
    perimeter of the house : lenght : 1554 cms , width: 1338

    so perimeter is 2(1554+1338)=5784 convert this to hasta by dividing the same by 72
    24 angulas are one hasta, 1 angula = 3 cms
    which equals = 80.33 which is approximately taken as 24 hastha 8 angula and in dwjayoni

    to know the yoni multiply the perimeter by 3 and divide by 8
    so 80 hasta 3 angulax3/8 = 240 hastha and 24 angula
    since 24 angula is is one hastha the multiplication gives 241
    when 241 is divided by 8 reminder is 1 so the perimeter is dwajayoni which can be useful for all directions
    if your house faces east yoni of 5 or 1 can be used
    if your house faces west only yoni of 1 should be used
    if your house faces south yoni 7 should be used
    if your house faces north yoni of 3 should be used

    yoni changes as per direction . they are the reminders when you mulitply the perimeter by 3 and divide by 8 you get the yoni. avoid yoni 2 4 8 which is bad.

  9. VIDYA NADGIR says:

    i have PLOT OF east-west(18 foot) and north-south (45 foot) i request you for best aya in this area to construst new residential house in south side is road. my rashi is kanya nakshtra is uttara i choice dwajaya (15*39) aya. in aya incluing walls of two sides or not ex: in 15 foot including wall or excluing wall please you tell me.

  10. amit kochar says:

    i have the following room size

    i have the option to change the size of the room and can reduce the size of 1st and last room and enlarge or reduce the middle one please advice

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