Often during carpentry work, especially when estimating I need to work out the square area of a wall or floor etc.
To calculate the area of a room like in the picture below whether its in centimetres, metres, feet or any other measure all you need to do is measure the length of the room, and the width. Then, simply multiply the length (side A) by the width (side B).
If you are calculating the area of a floor to know how much laminate flooring to allow for I normally add between 5-10% extra to allow for cutting waste. To do this, multiply the answer by 1.05 or 1.1,Answer x 1.05 = 5% extra added for waste.
If the room/wall/shape you want to work out the area for isn't square but odd or L shaped like in the picture below, I seperate the room into two or more manageable sections. Imagine a line seperating the two sections like the red one in the picture.
Then, treat these as two seperate rooms and calculate them as in the first example. After that, simply add the two answers together.
A x B = area2 1
C x D = area2 2
area 1 + area 2 = total area2
Quite often as a carpenter I have needed the circle formulas information on this page to help calculate the amount of materials I need for floors for example and when forming arches for bricklayers.
If you are calculating the area of a round room in order to calculate how much flooring you will need, always allow a decent amount extra because there will unfortunately be more wasteage than in a square room.
Radius = The distance from the outer edge to the centre.
Diameter= The furthest distance possible across the width (twice the length of the radius).
Circumference = Distance all the way round the outer edge. (I've only ever used that once to work out the length of skirting neded for a round room).
When making some of the calculations a number called Pi is often needed. Pi is a decimal value, that we will simplify to 3.14 for the purpose of these calculations.
These are some of the things you can calculate using Pi and the radius of a circle;
Have a question or comment about calulating the square area?
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