Bay Window Curtain Planner
Enter the three window widths, the wall run, the rod height to floor, the panel width you want to buy, the fullness ratio you choose, and your heading and length styles. The plan gives whole-run rod length, panel count, panel width, stated fullness, and length style together.
How the plan is worked out
Single-window calculators compared
On live desktop search on 28 Oct 2026, no page 1 result for the curtains terms checked gave a whole-run plan with rod length, panel count, panel width, stated fullness, and length style together. The calculators below give part of a plan, for one window at a time.
| Calculator | What you enter | What it gives | What it does not give |
|---|---|---|---|
| Pepper Home curtain size calculator | One window width and rod height | Panels for that one window. In a check on 27 Oct 2026, 72 inches wide and 90 inches high gave 2 panels, 75 inches each, 90 long | Whole-run rod length, a bay corner plan, or a plan for several windows on one wall |
| OmniCalculator curtain size calculator | One window or rod | A single-window size calculation | A whole-run plan for a bay window, a sliding door, or several windows on one wall |
| This planner | Three window widths, wall run, rod height to floor, panel width wanted, fullness ratio, heading, and length style | Whole-run rod length, panel count, panel width, stated fullness, and length style together | Finished panel length, or any extension, bracket, return, or corner allowance, because those numbers are still to verify |
Guides that feed this tool: how to measure curtains, curtain fullness explained, curtain length guide, curtain heading styles, bay window curtain hardware.
Whole-run rod length = the wall run you enter. This test tool adds no extension, bracket, return, or corner allowance, because those numbers are still to verify against manufacturer documents.
Total panel width = whole-run rod length times the fullness ratio you enter.
Panel count = total panel width divided by the panel width you want to buy, rounded up to the next whole panel.
Panel width = total panel width divided by panel count, so the panels share the total evenly.
Stated fullness = the fullness ratio you enter. Length style = the length style you choose. Heading choice is recorded only. No finished panel length is calculated in this test build, because length drops are still to verify.
Limits and sources: This test tool covers a bay run only from the numbers you enter. It does not cover angled bays outside a range, because no range is stated here. No manufacturer source is on file yet, beyond the single-window brand checks below, for corner connectors, bracket spacing, heading effects, or length drops, so no such number is published here.
Brand checks: Umbra and IKEA
Use these as a check on a single window, not as a rule for this tool. The two brands differ, so neither one replaces the wall run you enter above. This planner still uses the wall run you enter as the rod length.
| Brand check | What the brand says | Source |
|---|---|---|
| Umbra rod width | Measure the window including the frame, then add 8 inches in total to the width. | Umbra curtain rod guide |
| Umbra rod height and weight | Mount about 4 inches above the window frame, or halfway between the frame and the ceiling. Umbra rods in this guide are for light to medium curtains, up to about 22 pounds. | Umbra curtain rod guide |
| IKEA VIDGA width, fabric curtains | Add at least 15 centimetres, about 6 inches, on each side of the window, so curtains can open fully without blocking the window. | IKEA measuring guide |
| IKEA VIDGA width, panel curtains | Add 60 centimetres on each side, because panels need more space to open fully. | IKEA measuring guide |
| IKEA VIDGA height and depth | Mount the rail 15 centimetres above the window frame. VIDGA wall fittings are sold in 6 centimetre and 12 centimetre depths, so the depth you get is the fitting you buy, not a universal return number. | IKEA VIDGA guide |
For a bay window, neither check above is a bay rule. A bay needs corner hardware for its own angles, and this planner does not add a corner allowance. Check the corner hardware sheet for the product you buy.
Worked examples
Bay run, 120 inches
Wall run 120, fullness 2, panel width wanted 50.
Rod 120, total 240, 5 panels, 48 inches each
Bay run, 90 inches
Wall run 90, fullness 1.5, panel width wanted 40.
Rod 90, total 135, 4 panels, 33.75 inches each
Bay run, 144 inches
Wall run 144, fullness 2, panel width wanted 60.
Rod 144, total 288, 5 panels, 57.6 inches each
Related tools
Sliding Door Curtain Planner
Plan curtains for a sliding door from your own door width, wall run, and stack spaces you enter: rod or traverse length, stack space, panel count, panel width, stated fullness, and length style together.
Multi-Window Wall Curtain Planner
Plan curtains for several windows on one wall from your own window widths, gaps, and wall run: one continuous rod length, panel count, panel width, stated fullness, gap coverage, and length style together.
Disclaimer: Planning aid only. Results come only from the numbers you enter. This test tool uses the wall run you enter as the rod length and adds no extension, bracket, return, or corner allowance. The brand checks below are single-window starting points from Umbra and IKEA, and those two brands differ, so they are a check, not a rule for a bay, sliding door, or multi-window wall. Corner, bracket projection, and length-drop numbers still depend on the exact hardware you buy, so check that product's sheet before you buy or drill.