Make a measurement record
Remove the screen without bending it and photograph the installed orientation. Measure the outside frame width and height at several points, record the smallest clear opening, and note tabs, springs, pull handles, corners, and the spline channel. Mark which side faces outside.
If the frame is bent or the opening is out of square, do not average away the problem. A replacement screen may need a different frame or an adjustment to the opening. The supplier’s tolerance and installation method control the final size.
Common fit failures
Ordering by glass size can ignore the retention channel. Reusing an old spline without checking its condition can loosen the mesh. Measuring only one corner can miss a tapered opening. A screen that installs with force is not automatically a good fit; it can damage the frame or fail to seal.
Limits
No window or screen was measured. This guide does not specify a universal spline diameter, mesh type, frame material, or supplier tolerance.
Sources and related reading
See Also
If you want to move from general advice into actual product choices, start with Are Bay Windows Worth It? A Maintenance and Fit Decision, Bow Window Quote Site Conditions: Access, Trim, and Hidden Work, and When to Replace Drywall Instead of Patching: Signs, Costs, and Repair Timelines.
For a wider picture after the basics, Pella vs. Andersen Windows: Repair Costs and Maintenance (Head-To-Head) and Klein Tools ET310 Review: A No-Nonsense Circuit Breaker Finder are the next places to read.