Most cleaning businesses charge around 50 cents per square foot to clean and/or $20.00 to $40.00 per hour to clean things such as carpets.
Plus most cleaning businesses also charge a service fee for showing up which can range from $50.00 to $100.00
If you don't want to charge per square foot you can charge from $20.00 to $40.00 per hour for cleaning a home or office.