Calculating Square Feet
- Thread starter tittyboi
- Start date
entropic
Well-Known Member
If you want to know how much soil you need you measure in cubic feet square footage is the area of a 2d surface (like say a table).
To get the square footage of a circle you use pi*r^2 = sq footage, where pi is 3.141592653979 and R is the radius of the pot.
To get the cubic feet multiply that number by the height of the pot (everything has to be in the same units, like feet or meters, whatever). This formula will only work if it's a cylinder with straight sides, for graduated sides you need a little more involved math.
To get the square footage of a circle you use pi*r^2 = sq footage, where pi is 3.141592653979 and R is the radius of the pot.
To get the cubic feet multiply that number by the height of the pot (everything has to be in the same units, like feet or meters, whatever). This formula will only work if it's a cylinder with straight sides, for graduated sides you need a little more involved math.
you guys know what i mean. i know that sq. ft is measured by a square object. i just worder it incorrectly but thanks for the formula. couldnt find one on the internet. well do you know the formula for a pot thats sides arent straight up and down? i guess using that formula would give me a guess of what the area is
im sorry im not lazy but im just not good with numbers. maybe if i post the dimensions one of you guys can help me out. my pot isnt a straight up and down cylinder. its top diameter is 15inches so the radius is 7.5inches. the heighth of the container is 14inches. while the bottom circles diameter is 11.5inches so the radius is 5.75. im trying to figure out how much blood meal to add to my potting soil. it says 2lbs per 100sq.ft. of soil. thisw may be easy to some but not for me
SnowWhite
Well-Known Member
Dude, the cubic dimensions of your pots are not really important. How many litres/gallons is it? This is how pots are usually measured for size.
Plug the wholes in ur pot, take a measuring jug and fill it with water. Then note how much water you've poured into the pot. Hey presto, you know your pot size.
Plug the wholes in ur pot, take a measuring jug and fill it with water. Then note how much water you've poured into the pot. Hey presto, you know your pot size.
babygro
Well-Known Member
Well I just treat them as two cylinders and take the larger one away from the smaller one and halve it, adding it to the smaller cylinder figure. It's not precise but it's a good estimate. Your pot size then is 8.5 US liquid gallons, 7.30 dry gallons or 7.07 UK gallons depending on which figure you use.