I haven't really figured that out yet
I am not sure.
Preferrably around my age... but thats not set in stone
It is nice to think age is irrelevant but for many this is simply unrealistic. I would say up to 10 years maximum either side of your own age is likely to work for most, although there are exceptions to every 'rule'!
If I wasn't already married, then my limits would be: no younger than 36 and no older than 52. I'm 43, and it's important to me that we have at least some sense of shared cultural references/experiences. I wouldn't feel comfortable with someone much younger or older than me. So my age limit is a relatively narrow one.
Half plus seven rule. I learned it here.
Take your age. Divide by two. Add seven. The resulting number is the minimum age you can date.
Take your age. Subtract seven. Multiply by two. The result is the upper limit that you can date.
AS friends I have no limit but someone I am going to potentially become a life partner with is a little different. I'd say no over 10 years older simply because a couple should be able to do the same activities with each other. Often the age gap includes far separated physical and mental interests.