Estimating sales for a new bakery requires considerable thought. Your sales will depend on a variety of factors such as your business location and size, as well as what you specialize in. In the end, the biggest factor that influences your sales is how good your baked good are -- but note what factors would limit your sales potential even assuming unlimited demand.
Well-founded research will help you make an accurate estimate of what your sales will be. First, contact your local small business association or any other business association and ask if they have any advice or if they can put you in touch with a mentor or a similar business owner in a neighboring city. Look up news articles that might lay out some numbers. Visit coffee shops, cafes, and other bakeries in the area to get an idea of how busy they are.
Ask yourself what's reasonable for you to sell. Do you think you can sell 20 baked goods per hour? 100? 500? Consider how many hours per day you will be open and that some hours, near closing for example, you may sell few, if any items. Also consider how much baked goods you can conceivably make given your current resources, particularly regarding finances, manpower and equipment. You might theoretically be able to sell 1,000 cupcakes a day, but not if you can only bake 500 of them. Take whatever number you estimate as your hourly sales average, multiply that by how many hours per week you will be open and then by the average price of a pastry in your shop. This will give you your expected weekly sales. Consider it a very rough estimate until you have some numbers to work with once you've opened.
Keep Detailed Records
Once you've opened your doors, keep detailed records of what you sell. Many point of sale systems and registers have features that allow you to track what your selling and how much of it. If your POS doesn't keep track, start a spreadsheet on your computer and track at least the days total sales by hand. This should help you recognize trends and forecast for the future. It's important to keep detailed records so that in your second year you can look back and base your estimate off that.
When to Overestimate
During your first week, plan for the best. Expect to make as many pastries as you can. If you make too many, you can give out free samples to encourage people to come bacl. If you make too few, you're losing potential customers.