How much macrame cord do I need? Learn how to estimate length of macrame cord needed for any project with our handy guide. Below, we have methods for estimating how much cord you need based on a variety of factors such as thickness of the rope and how many knots the pattern calls for. In general, your macrame cord needs to be about four times the length of your project. If the cords are doubled, meaning folded in half to create two cords, then aim for eight times the length of your project. So, if you are making a wall hanging that is about a foot long with doubled strands, figure eight feet of rope per strand. When in doubt, ALWAYS cut more rope than you think you will need.