When to use the window size tool
The Window size tool is built for practical door and window planning. It helps plan window opening size, rough opening, frame allowance, clearance, and replacement notes, while keeping the calculation tied to the actual work rather than a generic remodel assumption.
It is most useful when the project is still being shaped: measurements are close but not final, product grades are not fully selected, and the homeowner wants a clearer brief before comparing suppliers, materials, service companies, or contractor quotes.