Curtains look full only when the fabric is gathered: 2× fullness is standard, 2.5× looks luxurious and 3× is used for sheers. Each heading style also needs a different allowance at the top – a rod pocket must fit around the rod, while grommets and pleats need a doubled header.
How to use the Curtain Panel Calculator
- Heading type
- Fullness
- Rod width (bracket to bracket)
- Finished length
- Rod circumference
- Fabric width
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose the heading, fullness, rod width and finished length, the rod circumference (for rod pockets) and the width of your fabric.
Tips
- Measure over thin clothing with a soft tape held snug but not tight, and keep the tape level all the way round.
- Take each measurement twice; if you are between sizes, the larger size is usually the safer choice.
- Size charts vary by brand and country – check the maker’s own chart when it is available.
- For sewing projects, pre-wash fabric before cutting and buy 10% extra for shrinkage, pattern matching and mistakes.
Common mistakes to avoid
- Mixing inches and centimetres between the tape and the size chart.
- Forgetting seam and hem allowances when cutting fabric.
- Measuring an old, stretched garment instead of your body.
Inputs explained
| Field | What to enter |
|---|---|
| Heading type | Choose one: Grommet / eyelet, Pinch pleat, Rod pocket, Tab top |
| Fullness | Choose one: 2× (standard), 2.5× (deluxe), 3× (sheers, ultra) |
| Rod width (bracket to bracket) | Units: in, cm |
| Finished length | Units: in, cm |
| Rod circumference | Units: in, cm |
| Fabric width | Units: in, cm |
What each result means
- Total finished width = [Rod width (bracket to bracket)]×[Fullness]
- Fabric widths (panels) = ceil([Total finished width]÷([Fabric width] – 2×0.0254) – 0.000001)
- Total fabric = [Fabric widths (panels)]×[Cut length per panel]
Example values
How the main result changes when Rod width changes and everything else stays at the example values above:
| Rod width (bracket to bracket) (in) | Fabric widths (panels) |
|---|---|
| 30 | 2 |
| 45 | 2 |
| 60 | 3 |
| 75 | 3 |
| 90 | 4 |
| 120 | 5 |
Formula
Total finished width = rod (bracket-to-bracket) width × fullnessPanels (fabric widths) = ceil(total width ÷ (fabric width − 2 in side hems))Cut length = finished length + heading and hem allowancesTotal fabric = panels × cut lengthWorked example
Inputs — Heading type: Grommet / eyelet; Fullness: 2× (standard); Rod width (bracket to bracket): 60 in; Finished length: 84 in; Rod circumference: 3 in; Fabric width: 54 in.
Results — Total finished width = 120 in; Fabric widths (panels) = 3; Cut length per panel = 94 in; Total fabric = 7.83 yd.
Frequently asked questions
How many curtain panels do I need?
Multiply the rod width by the fullness and divide by the usable fabric width – a 60 in rod at 2× fullness with 54 in fabric needs 3 widths.
How much extra length for a rod pocket?
About 8½ in plus half the rod circumference for the pocket, header and bottom hem.
Should I add pattern repeat?
Yes – add one repeat to each cut length so patterns line up across panels.
What formula does the Curtain Panel Calculator use?
Total finished width = rod (bracket-to-bracket) width × fullness.