How do I know if I've saved enough to retire?

You are already doing the hard part: saving and paying attention. Most people avoid the question entirely. The not-knowing you feel is not failure; it is just missing information. And information is something you can go get. The numbers feel like a fog because you are trying to hold them all in your head. Get them onto paper instead. Write down what you spend in a year, what you have saved, and what income you will have coming in. You do not need to be an expert to see the shape of it. A rough picture beats a vague worry every time. Take one step this week: add up your yearly spending, just that one number. It turns the giant question of when you can go into something you can actually work with. If the picture is unclear after that, one session with a fee-only planner can tell you where you really stand. You are closer to an answer than the worry lets you believe.