Actually my beagles are never TRULY alone - since there are ten of them, there's always "playmates". However, if you mean with NO humans around, usually no more than perhaps 6 hours at a time - if that. My daughter and son in law live with me - and work different shifts. I work part time, so am out of the house 5-6 hours a day. Often they're "humanless" for less than 1-2 hours a day. There are 4 that are "kenneled" when no humans are around - the two little girls, and my two males. Most are allowed freedom of the basement (it's "finished" - with a big family room, kitchen, bath and laundry room, there is a futon and two big doggie beds so they mostly sleep. The "little girls", Bella and Angel are crated because Angel is still enough of a puppy that she tears things up when left to her own devices. She does better when her half sister, Bella is with her, so they share a "crate". The "older boys", Romeo and Tanna are "boys" and like to "mark" things when they're loose. I don't think any of my dogs would know what to do if they were truly ALONE.