I'm on 4 with 5 on the way. Here's how I think about in terms of effort. Basically, after 2 it's logarithmic. I can do lots of things in batches that shave off

I'm on 4 with 5 on the way. Here's how I think about in terms of effort. Basically, after 2 it's logarithmic. I can do lots of things in batches that shave off time. So, brushing teeth happens for all 4 kids at the same time and the set up cost would be the same with 1. With more kids, you end up setting rules for how they play together, rather than micromanaging entertainment for one. Once one kid can read, the older can read to the younger. This puts the older one on a good task and entertains the younger one. It's not the life for everyone, but I really enjoy it. In terms of effort, the per capita cost goes down after each kid IMHO. 1 kid = 1 2 kid = 2.5 3 kid = 3 4 kid = 3.25