- Pick your unit system and fabric weight basis.
- Enter the finished width and drop for one panel.
- Choose a fullness factor that matches your style.
- Add hem and header allowances you plan to sew.
- Enter fabric density, then optional lining layers.
- Set header tape and rings if you use them.
- Press calculate, then download CSV or PDF.
| Scenario | Finished W × L | Fullness | Layers | Estimated per panel |
|---|---|---|---|---|
| Light voile | 140 cm × 220 cm | 2.0 | Main only (120 gsm) | ~0.79 kg |
| Medium cotton + lining | 150 cm × 240 cm | 2.2 | Main (220 gsm) + lining (120 gsm) | ~2.55 kg |
| Heavy velvet + interlining | 160 cm × 250 cm | 2.5 | Main (450 gsm) + interlining (180 gsm) | ~4.99 kg |
Curtains are often used in greenhouses, potting sheds, and sunrooms to manage light and heat. Weight matters for tension wires, curtain tracks, and DIY frames.
- Use the total weight to size brackets, anchors, and track rollers.
- In humid areas, choose hardware rated for corrosion and load.
- Heavier panels reduce flapping and improve shade consistency.
Load planning for curtain tracks and rods
In garden rooms and greenhouses, curtains often run on light-duty tracks. Many household tracks are comfortable around 6–12 kg total load when brackets are correctly spaced. Use the “All panels” result to estimate the full moving load, then add a safety margin for moisture, dust, and occasional snagging. For long spans, place brackets every 70–90 cm and keep end brackets near the ends.
How fabric density changes weight outcomes
Fabric density is the main driver. A 220 gsm fabric adds 220 g for every square meter of cut area. If one panel needs 2.6 m² of fabric, the main layer alone contributes about 572 g. Switching to 450 gsm velvet nearly doubles that to about 1,170 g before lining or hardware.
Allowances and fullness that quietly add mass
Fullness increases cut width, so weight rises proportionally. Moving from 2.0 to 2.5 fullness adds 25% more width, area, and fabric weight. Hem and header allowances also matter. A 20 cm bottom hem on a 1.6 m wide cut width adds 0.32 m² of extra area across the fold. Even small side hems matter: two 5 cm side hems add 10 cm total width, which increases area along the entire drop.
Lining, interlining, and thermal performance
Lining typically adds 90–160 gsm, improving opacity and reducing greenhouse glare. Interlining adds bulk and insulation; 150–250 gsm is common for insulating layers. If your panel area is 3.0 m², a 120 gsm lining adds about 360 g, while a 180 gsm interlining adds about 540 g. In bright spaces, extra mass improves hang stability and reduces flutter.
Hardware weight and maintenance considerations
Tape and rings are smaller, but they affect smooth travel. Header tapes are often 20–60 g per meter of top width; a 3.0 m tape run at 35 g/m adds about 105 g. Metal grommets can be 6–15 g each; 16 rings may add 96–240 g. In humid gardening areas, choose corrosion-resistant parts and clean tracks quarterly.
FAQs
1) Should I enter finished width or cut width?
Enter finished width. The calculator applies fullness and side hems to estimate cut width automatically.
2) Why does fullness change weight so much?
Fullness multiplies the fabric width. More width means more area, so fabric grams rise in direct proportion.
3) My lining is narrower than the face fabric. What should I do?
Reduce finished width slightly or lower fullness to approximate your lining coverage, then compare results as a range.
4) Does the calculator include thread, pleats, or trims?
It includes fabric layers, optional header tape, and optional rings. Add trims, tassels, and heavy borders separately.
5) How can I estimate rod or track capacity?
Use the “All panels” total and add 20–30% margin. Then check bracket spacing and manufacturer load guidance.
6) Can I use oz/yd² instead of gsm?
Yes. Select oz/yd² and enter your values. The calculator converts to gsm internally for consistent area-based weight.