Building calculators I use

I use the Opticutter calculator to determining the number and size of boards needed for a project.

I use Opticutter to determine how many boards I need for a project or how many boards I can get from 4x8 sheet goods

To calculate the number of railing balusters, I use the Blocklayer - Baluster Spacing calculator:

I used the Blocklayer calculator for spacing deck rails and a garden gate