We just had another thread
right here about how to calculate your maintenance calories.
I haven't found any of the calculators useful at all, and IMO most people have to resort to experimenting to see where they need to be.
I'd start be adding 200 calories a day and see where you are at the end of a week. If you're still losing, add another 100 each day until you are maintaining. If you overshoot, then lower it again.
If you haven't been counting calories while losing, just add a healthy snack or an additional starchy carb, or slightly larger portions.
Mel