Calculate the amount of Rebar needed for reinforcing a wall.
This calculator assumes that you are using 20 foot long lengths of Rebar.
If your wall is over 20 feet long it will add the amount of overlap required.
If your wall is over 40 feet long it will add 2x the amount of overlap required.
For each additional 20 foot increase of the wall length it will add an additional amount of overlap.
It will do the same for the wall height.
Of course you can cheat a bit but it is based on that your lineal lengths meet each other in the corners and if you are using corner bars they get spliced on at that point.
In addition it calculates for two bars for the top row length wise.