I doubt there is a form for regular clean pricing because you just have to figure out how long it will take then times that by your hourly rate! If you don't want to tell the customer then just give them the overall price not the number of hours.
Also, I would suggest that when you meet a prospective client, ask them questions to find out whether they have had a cleaner before, how many hours they worked, etc then base your quote around that.
Its all experience, counting bedrooms, bathrooms, etc and trying to see how untidy or clean a place is to judge the price.