I have maybe enough for a year for each.
And then I have a little more set aside, which I keep in the role of "precious metals."
I wouldn't say I "have a lot" of ammo, but it was sobering a couple of years ago when I could no longer lift either of the chests that serve as primary storage.
In fact, it's possible that two people would be unable to lift one. Stuff weighs more than you think when you pick it up a box at a time.
Count it? I've taken inventory once or twice. The last time was three years ago, and the inventory sheet is still in the chest. Life and "stuff" has kept me from actually burning any of it at the range, which sucketh mightily.
In terms of "theory" numbers, I try to keep 1,000 on hand for each of the devices chambered that caliber. I don't always succeed. However, in the .22 LR realm, I keep considerably more than that. Happens that .22 LR is what I use most for practice, and it's the caliber I keep in the truck to go with my emergency rifle. A 500-round box of the stuff doesn't cost much, weigh much, or take up much space, and it's comforting to have a few extra bricks.
"Truth is a dangerous thing: once found, you must never turn your back on it." -- gh@c2
"Look at it this way. If America frightens you, feel free to live somewhere else. There are plenty of other countries that don't suffer from excessive liberty. America is where the Liberty is. Liberty is not certified safe." -- gh@c2