| Item | Value | Notes |
|---|---|---|
| Window width | 72 in | Standard double window. |
| Number of identical windows | 2 | Two matching windows on the same wall. |
| Rod extension each side | 8 in | Rod extends beyond frame for better stacking. |
| Rod width per window | 88 in | 72 + 8 + 8. |
| Fullness factor | 2.5x | Rich, hotel-style gathers. |
| Total finished curtain width per window | 220 in | Rod width multiplied by fullness factor. |
| Panel configuration | Pair of panels | Two equal panels meeting in the middle. |
| Fabric width | 54 in | Standard drapery fabric width. |
| Fabric widths per panel | 3 drops | 110 / 54 rounded up. |
| Cut length per drop | 102 in | Includes heading, hem and small puddle. |
| Total face fabric required | 17 yards | For two identical windows combined. |
| Total lining fabric required | 17 yards | Assuming full separate lining on all panels. |
Use these figures only as an illustration. Enter your own measurements above for accurate results.
- Rod width (inside mount) = window width.
- Rod width (outside mount) = window width + 2 × rod extension each side.
- Total finished curtain width per window = rod width × fullness factor.
- Panels per window = 1 for single panel, 2 for pair of panels.
- Panel width = total finished width ÷ panels per window.
- Fabric widths per panel = ceiling(panel width ÷ fabric width).
- Finished drop = rod-to-floor / sill measurement + extra bottom length.
- Base cut length = finished drop + top heading allowance + bottom hem allowance.
- If there is a vertical pattern repeat, cut length is rounded up to the next whole repeat.
- If fabric shrinkage is expected, cut length × (1 + shrinkage% ÷ 100).
- Fabric length per panel = adjusted cut length × fabric widths per panel.
- Total fabric length per window = fabric length per panel × panels per window.
- Total fabric length all windows = total fabric per window × number of identical windows.
- Lining fabric (if included) uses the same panel count and cut length as face fabric.
- Choose your preferred measurement unit, inches or centimetres.
- Select mount type: inside mount sits within the frame, outside mount overlaps the wall.
- Pick a heading style that matches your rod and workroom method.
- Measure the visible glass and frame to get the window width.
- Enter the number of identical windows that will share the same treatment.
- For outside mount, add rod extension on each side so curtains clear the frame.
- Measure from the top of the rod down to the finished floor or sill.
- Decide whether you want the curtains floating, just touching or puddling, then enter the extra bottom length accordingly.
- Enter heading and hem allowances, pattern repeat and expected shrinkage as required by your sewing standard.
- Tick the lining option if you plan to use a full separate lining on all panels.
- Click “Calculate curtain size” to see rod width, panel sizes, per-window yardage and total yardage for all windows.
- Use the CSV or PDF download buttons to save the results for quoting, ordering or sewing notes.
Accurate measurements keep curtains hanging level and meeting neatly in the middle. Measure window width, frame depth, rod position and finished floor height so you avoid dragging hems or unexpected gaps.
- Record separate measurements for each window if sizes differ.
- Note any radiators, sills or obstacles affecting finished drop.
- Write down chosen mounting height above the frame.
Fullness and panel style change how formal the curtains feel. Bedrooms often suit higher fullness for darkness, while living rooms may use lighter gathers and wider stack-back for maximum daylight.
- Use single panels for narrow windows or doorways.
- Use pairs on large windows where you want symmetry.
- Increase fullness for sheers or lightweight fabrics.
Inside mount fits the rod within the frame, showing surrounding trim and saving wall space. Outside mount lets curtains overlap the wall, improving blackout performance and visually enlarging small windows.
- Outside mount hides imperfect frames and hardware.
- Inside mount suits recess tracks and minimal looks.
- Use generous extensions for layered treatments.
The calculator translates rod width and fullness into fabric drops. It also rounds cut lengths up to the next pattern repeat so motifs align, saving time compared with manual pencil-and-paper yardage sketches.
- Check your fabric roll width before ordering yardage.
- Use pattern repeat field for large prints and stripes.
- Allow extra fabric if you plan contrast bands.
Adding lining improves light control, privacy and insulation. Interlining between face fabric and lining increases weight, which makes folds hang better but also adds load to tracks, poles and fixings.
- Tick the lining option for separate lining yardage.
- Use heavier linings in bedrooms and media rooms.
- Consider blackout lining for street-facing windows.
Curtain projects often sit alongside other upgrades. For example, you can convert running hours on generators or boats when planning fabric exposure using the Engine Hours to Miles calculator.
When updating lighting around new window treatments, estimate electrical work budgets with the Cost to Install Recessed Lighting calculator before you order fabric and hardware.
What information do I need before using this curtain calculator?
Measure the glass, frame and rod position, then type those numbers into the form. Choose your mount type, fullness and number of windows, then run the calculation to see suggested panel sizes and fabric yardage.
How does the fullness factor change the look of my curtains?
The fullness factor controls how gathered the curtains look when closed. Higher values use more fabric, create deeper folds and block more light. Lighter sheers may look best at 2x fullness or higher.
Can I use this tool for short curtains over radiators or sinks?
Yes. Enter the rod-to-floor distance as your drop, then add negative extra bottom length so the curtains float above the counter. Check that the final drop clears handles, radiators and any window trim.
When should I enter a vertical pattern repeat measurement?
Use the vertical pattern repeat field whenever your fabric has a repeating motif that must line up across drops. The calculator rounds each cut length up to the next repeat so patterns match at the seams.
How do I estimate lining fabric and overall weight safely?
For lining, tick the lining option so the tool duplicates face-fabric yardage. To estimate total project load on a balcony or terrace, use your curtain weight together with the Concrete Roof Paver Load Calculator on a separate page.
Should I work in inches or centimetres for my project?
Inches are usually easiest for imperial tape measures and many workrooms. Centimetres work better where metric tapes and fabric bolts are standard. The calculator converts yardage totals for you, so choose whichever unit feels most natural.
When is this curtain size calculator most useful?
Use this tool when requesting quotes, planning fabric orders or checking whether ready‑made sizes are suitable. Save the CSV or PDF, then share results with your fabric supplier, seamstress or installer so everyone works from the same measurements.