For the mathematically challenged, just get a large roll of string. Lay out the string all around the future concrete perimeter making sure you are dead on (or slightly outside - but definitely not inside the future concrete area). When done, gather up the string and measure its length. Divide the string length by 4 to effectively turn the "curved" or "any random area" into a simple "square". Multiply side one (1/4 the string) by side 2 (1/4 the string) to get "area" of the "square". Multiply that number by the concrete thickness (example: .33 for 4 inch slab or .5 for 6 inch slab or ?/12 for any other depth) and divide that number by 27 (3 ft x 3 ft x 3 ft = 27 for a cubic yard) to get the cubic yards of concrete needed. To check this method out, lets say the string measures 12 foot and you're pouring a 3 foot (OMG) slab. 12/4 = 3. ; 3*3=9 ; 9*3=27 ; 27/27=1 ; 1 Cubic Yard of concrete would be needed.
For the mathematically challenged, just get a large roll of string. Lay out the string all around the future concrete perimeter making sure you are dead on (or slightly outside - but definitely not inside the future concrete area). When done, gather up the string and measure its length. Divide the string length by 4 to effectively turn the "curved" or "any random area" into a simple "square". Multiply side one (1/4 the string) by side 2 (1/4 the string) to get "area" of the "square". Multiply that number by the concrete thickness (example: .33 for 4 inch slab or .5 for 6 inch slab or ?/12 for any other depth) and divide that number by 27 (3 ft x 3 ft x 3 ft = 27 for a cubic yard) to get the cubic yards of concrete needed. To check this method out, lets say the string measures 12 foot and you're pouring a 3 foot (OMG) slab. 12/4 = 3. ; 3*3=9 ; 9*3=27 ; 27/27=1 ; 1 Cubic Yard of concrete would be needed.
I think I almost understand it, at last! Thank you very much for the video. I appreciate how much work goes into a “simple” pour!
I think I need to study chemistry and algebra to do my driveway.
Mostly geometry
your videos help so much is there any way you can to a video showing us how to do it in lineal feet i would like to learn
Do you have something specific?
Is the 20' the radius of just the Inner Circle? or is that the Center of the entire circle?
For estimating you will need the radius of the inner and outer circles