Hi I thought I would add my idea for a belt.
I use something called a doublechain knot.

here's how I tie it
1. make 2 counterclockwise overhand loops,the second on top of the first
2. pull a bight up through both loops
3. pull a second bight up through the second loop and the first bight
4. pull a third bight up through the first two bights
5. keep repeating that for as long as you need, tightening as you go
6. at the end of the cord pull the end all the way through the last bight to secure it
7. to undo the chain pull the end back through and keep pulling on it

I did this yesterday and used two 10 meter pieces of cord side by side and got about 1.1 meters of chain, plenty to fit around my waist, i just use a carabiner as the buckle