For the best experience when wireless, eeros should be no more than 50 feet from another eero.
Depending on your home, this can vary. eeros are flexible to be placed around the home, and the eero App will take you through best placement to ensure you are getting the most out of your system.
If your eeros are all wired together through Ethernet, spacing between eeros is more flexible. Wireless coverage still depends on your home's structure.