Get the Right Screen Size the First Time
Measure your window frame once. Get the exact screen dimensions, mesh area, and spline length for your DIY repair. No guesswork, no wasted material.
Enter Your Window Measurements
Measure the inside of your frame channel in inches. Use the smallest measurement if your frame varies.
Your Results
Enter your measurements and click Calculate to see your screen size and materials.
Screen Size to Cut
—
×
—
inches
Subtract 0.5 inches total for the spline channel (0.25" per side).
Mesh Area Needed
— sq in
— sq ft
Spline Length
— in
— ft
Screen Perimeter
— in
For reference
Windows
1
Quantity
Shopping List
Copied to clipboard!
How to Measure Your Window Frame
- Open the window fully. You need clear access to the inside of the frame channel where the screen sits.
- Measure the width. Run your tape measure from the inside left edge to the inside right edge of the channel. Record the measurement at the top, middle, and bottom. Use the smallest number.
- Measure the height. Measure from the inside top edge to the inside bottom edge. Check the left side, center, and right side. Again, use the smallest number.
- Check the channel depth. Look into the channel where the spline sits. Most frames have a 1/4 inch channel on each side. If yours looks different, measure it and enter the value above.
- Enter your numbers. Type the width and height into the calculator. It handles the rest.
Common Mistakes to Avoid
- Measuring the outer frame. The screen fits inside the channel, not over the outside of the window. Always measure the inner opening.
- Forgetting the spline channel. The screen must be smaller than the opening so the spline can hold it in place. This calculator subtracts the channel depth for you, but only if you enter the right depth.
- Measuring only one spot. Frames can warp or shift over time. Always measure at multiple points and use the smallest dimension.
- Buying mesh that is too narrow. Screen mesh comes in standard widths (24", 36", 48", 60", 72"). Make sure the roll is wider than your screen height. The shopping list above tells you the minimum roll width to buy.
- Cutting before test-fitting. Lay the cut screen in the frame before pressing in the spline. It is easier to trim a little more than to stretch a screen that is too small.
Quick Reference
Standard Channel Depths
| Frame Type | Depth per Side |
|---|---|
| Vinyl replacement windows | 1/4" (0.25") |
| Aluminum frames | 1/4" (0.25") |
| Older wood frames | 3/16" to 1/4" |
| Porch/patio panels | 1/4" to 3/8" |
Common Mesh Roll Widths
| Roll Width | Fits Screens Up To |
|---|---|
| 24 inches | 23.5" tall |
| 36 inches | 35.5" tall |
| 48 inches | 47.5" tall |
| 60 inches | 59.5" tall |
| 72 inches | 71.5" tall |
Spline Size Guide
| Channel Width | Spline Diameter |
|---|---|
| 3/16" (0.188") | 0.140" or 0.160" |
| 7/32" (0.219") | 0.180" or 0.200" |
| 1/4" (0.250") | 0.220" or 0.240" |
When in doubt, bring a piece of your old spline to the hardware store for a match.
Questions People Ask
- Use a tape measure to find the inside width and height of the frame channel where the screen sits. Measure at the top, middle, and bottom for width, and left, center, and right for height. Use the smallest measurement. Measure to the inside edge of the spline channel, not the outer frame.
- If your measurements vary by more than 1/8 inch, your frame may be out of square. Use the smallest measurement for both dimensions. You can add 1/8 inch to the calculated screen size as a safety margin, then trim after test-fitting.
- Fiberglass mesh is the most common and easiest to work with. It resists denting and costs less. Aluminum mesh is stronger but harder to cut. For homes with pets, pet-resistant mesh is thicker and holds up better. The calculator works with any mesh type.
- Add about 10% to your mesh area for cutting waste. For spline, add an extra foot beyond the calculated perimeter. If you are repairing several windows, buy a full roll of mesh and a longer spline coil. It is cheaper per foot.
- Yes. Porch and patio screens work the same way. Measure the frame opening, subtract the channel depth on each side, and the calculator gives you the right screen size. Porch panels are often larger, so check that your mesh roll is wide enough.