There is no definitive answer to how much interior designers cost, as it varies significantly depending on their experience, location, and the specific project they are working on. Generally speaking, you can expect to pay anywhere from $50-$200 per hour for interior design services.
If you are working on a specific project, such as designing a new kitchen or bathroom, you may be able to get a flat rate quote from an interior designer. This can be helpful in budgeting for your project, as you will know exactly how much the design services will cost upfront.
Ultimately, the best way to determine how much you should expect to pay for interior design services is to get a few quotes from different designers and compare their rates. This will give you a good idea of what the going rate is in your area, and help you find a designer that fits within your budget.