How to Calculate Curtain Fabric Quantity
Getting the fabric quantity wrong costs money. Order too little and your tukang jahit runs short mid-project. Order too much and you are sitting on dead stock. This guide breaks down the exact formulas we use daily at our PJ warehouse when helping curtain makers and ID firms work out their yardage.
Start with these three numbers
Every curtain fabric calculation comes down to three measurements: track width, finished drop, and the fabric roll width you are using.
Before touching a calculator, measure the track or rod. Not the window. The track. That distinction trips up more people than you would think — a 200cm window often sits behind a 240cm track because installers extend it 20cm each side to let the curtain stack clear of the glass.
Next, measure the drop. Floor-length curtains in a typical Malaysian condo usually run 245cm to 260cm from track to floor. Some designers deduct 1cm for clearance. Others prefer a 3cm puddle. Get this number confirmed before ordering fabric, because a 15cm mistake on drop means either short curtains or wasted material across every single width.
Fabric width matters more than you think
Most curtain fabric we sell from our Jalan Klang Lama warehouse comes in 280cm (110") or 300cm (118") widths. But not all. Some European linen curtain fabrics are only 137cm (54") wide. And certain printed collections run at 140cm.
Why does this matter? A 280cm-wide fabric used horizontally (railroaded) can cover a 260cm drop in a single width with no seaming. But a 137cm fabric must be joined — which doubles your fabric consumption and adds seaming labour. Most suppliers won't tell you this, but fabric width is actually the single biggest factor that determines whether your project comes in on budget or blows past it.
Always confirm width before you calculate. It is printed on the selvedge or listed in the sample book.
The curtain fabric quantity formula
Here is the formula, broken into steps. We use this exact sequence every day when quoting for curtain makers, from a single bedroom in Bangsar to a 347-room hotel project.
Widths = (Track width × Fullness ratio) ÷ Fabric width
Round up to the nearest whole number. Always round up — you cannot use half a width.
Cut length = Finished drop + Heading allowance + Hem allowance
Standard allowances: 15cm heading, 15cm hem. For velvet curtain fabric or heavy textured weaves, use 20cm for the hem.
Adjusted cut = Ceiling(Cut length ÷ Pattern repeat) × Pattern repeat
Skip this step for plain fabrics. Only needed when the fabric has a vertical repeat.
Total metres = Widths × Adjusted cut length ÷ 100
This is your order quantity. Add 3-5% contingency for a project with many windows.
Fullness ratios explained
Fullness determines how gathered the curtain looks. Flat panel? That is 1x. But nobody wants flat curtains except for very specific wave heading systems. Here is what each ratio actually looks like on the track:
- 1.5x fullness — Used for wave fold / ripplefold headings. Clean, contemporary look with gentle curves. Popular in condos around Mont Kiara and Damansara Heights where the design brief is minimal.
- 2x fullness — Standard for pencil pleat curtains. This is the workhorse setting for most residential and mid-range hotel projects in Malaysia. Good balance between cost and appearance.
- 2.5x fullness — Pinch pleat and goblet headings. Gives a rich, deep gather. Common in luxury hotels, high-end residential, and formal dining rooms. Uses significantly more fabric per window.
- 2.5x to 3x fullness — Required for sheer and semi-sheer fabrics. Anything less looks cheap and transparent. If a client is ordering sheer at 2x, the finished curtain will disappoint them.
The jump from 2x to 2.5x adds 25% more fabric. For a large living room window that already needs 12 metres of fabric at 2x, going to 2.5x pushes it to 15 metres. That price difference is real — make sure your client knows before you commit to a heading style.
Heading and hem allowances
Standard practice in most KL workrooms:
- Heading (top turn-up): 15cm for tape headings, 10cm for eyelet/grommet
- Hem (bottom fold): 15cm for a standard double-fold hem on lightweight to medium fabrics
- Heavy fabrics: Allow 20cm for the hem on velvet or blackout fabrics weighing above 240gsm — the extra weight needs a deeper hem to hang properly
Total allowance typically sits between 30cm and 40cm, added to the finished drop measurement. Your tukang jahit may have their own preference. Always check with the workroom before finalising quantities — a tailor in Taman Desaria might work differently from one in Damansara.
Pattern repeat: the hidden cost
Plain fabrics are simple. Cut to length, done. But patterned fabrics demand repeat matching across every joined width. Miss this and your curtains look like they were made by an amateur.
Pattern repeat is the vertical distance before the design repeats. Common repeats: 32cm, 48cm, 64cm. Some large damask prints run as high as 91cm.
The formula is straightforward but the waste adds up fast. You take your cut length, divide by the repeat, round up to the next whole number, and multiply back. That rounding is where fabric goes to waste.
Cut length 275cm, pattern repeat 64cm
This is why we always recommend clients consider plain fabrics for very wide windows or bulk hotel projects. The repeat waste on a 200-room hotel order can add up to hundreds of metres of additional cost. And during peak seasons when stock runs low before Raya or before CNY, that extra 10-15% can mean the difference between getting your order filled or waiting 6-8 weeks for the next container from China.
Worked example: standard Malaysian condo bedroom
Let us walk through a real calculation. This is a master bedroom window in a typical Selangor condo — the kind of job every curtain maker handles weekly.
Master bedroom, condo in Ara Damansara
Given: Track width 320cm, finished drop 255cm, pencil pleat heading (2x fullness), plain blackout fabric at 280cm width, no pattern repeat.
Same window, but with pinch pleat and patterned fabric
Same condo, but client wants pinch pleat with a 48cm repeat fabric
Given: Track 320cm, drop 255cm, pinch pleat (2.5x), fabric width 280cm, pattern repeat 48cm.
Quick reference table for common window sizes
These figures assume 280cm fabric width, 255cm drop, standard 30cm allowances, and no pattern repeat. For patterned fabrics, add 10-15%.
- Measure the track, not the window
- Confirm fabric width from selvedge
- Choose heading style before calculating
- Check for pattern repeat in sample book
- Always round up widths to whole number
- Add 3-5% contingency for multi-window jobs
Fabric quantity at a glance
Common window sizes with pre-calculated fabric quantities. Based on 280cm fabric width, 255cm drop, 30cm total allowances, plain fabric.
For patterned fabrics, add 10-15% to these figures depending on the repeat size. For 137cm-wide fabrics (European linens), roughly double the number of widths. These are estimates — WhatsApp us with your exact measurements for a precise calculation.
Mistakes that cost money
We see these errors weekly from curtain makers and designers who should know better. Each one means either wasted fabric or a second trip to the kedai kain.
Measuring the window, not the track
A 200cm window with a 240cm track needs fabric for 240cm. Sounds obvious, but this mistake accounts for roughly 1 in 5 miscalculations we correct on WhatsApp.
Assuming all fabric is 280cm wide
European linens at 137cm wide need double the widths. We have seen curtain makers order half the required fabric because they assumed standard width without checking the sample book.
Forgetting pattern repeat waste
A 64cm repeat on a 285cm cut length wastes up to 35cm per width. On a 6-width job that is over 2 extra metres of fabric you did not budget for.
Using sheer at 2x fullness
Sheers need 2.5x minimum. At 2x, the fabric looks skimpy and transparent. Your client will complain, and you will end up remaking it with more fabric anyway.
No contingency for multi-window jobs
A condo with 7 windows? Add 3-5% contingency. Cutting errors happen, dye lots shift, and one bad cut means you need more from the same bolt. Better to have 2 metres extra than to reorder and wait for new stock.
Ordering during peak season without buffer
Stock runs thin before Hari Raya and Chinese New Year. Lead times from China ports stretch to 8 weeks during peak. Order early or order extra — do not assume your pembekal will have stock when you need a top-up.
Fabric calculation FAQ
Common questions about calculating curtain fabric quantity, from fullness ratios to pattern repeats.
How do I calculate how much curtain fabric I need?
Measure your track or rod width, multiply by your chosen fullness ratio (typically 2x for pencil pleat or 2.5x for pinch pleat), then divide by fabric width (usually 280cm or 300cm) to get the number of widths. Multiply widths by the finished drop plus heading and hem allowances (typically 30-40cm extra) to get total metres needed.
What fullness ratio should I use for curtains?
Use 1.5x fullness for wave or ripplefold headings, 2x for standard pencil pleat, and 2.5x for pinch pleat or goblet heading. Sheer fabrics typically need 2.5x to 3x fullness to avoid looking flat. The fullness ratio determines how gathered and luxurious the curtain appears when closed.
Do I need extra fabric for pattern repeats?
Yes. If your fabric has a pattern repeat, you need to round up each cut length to the next full repeat so patterns align across panels. For example, if your cut length is 275cm and the pattern repeat is 64cm, divide 275 by 64 to get 4.3 repeats, round up to 5, giving you a cut of 320cm per width. This adds roughly 10-15% waste on most patterned fabrics.
What is the standard curtain fabric width in Malaysia?
Most curtain fabric sold wholesale in Malaysia comes in 280cm (110 inch) or 300cm (118 inch) width. Some European linens are 137cm (54 inch) wide, which means railroading is not possible and you will need to join widths. Always confirm fabric width before calculating — a wrong assumption can throw off your entire order.
How much heading and hem allowance should I add?
Standard allowance is 15cm for the heading turn-up at the top and 15cm for a double-fold hem at the bottom, giving 30cm total. For heavier fabrics like velvet, allow 20cm for the hem. Some tukang jahit prefer 40cm total to have room for adjustment. Always confirm with your workroom before cutting.
Can Artwork Fabrics help me calculate fabric quantity for my project?
Yes. Send us your window measurements, preferred heading style, and fabric choice on WhatsApp and our team will calculate the exact quantity needed. We do this daily for curtain makers, interior designers, and project buyers across Malaysia. No charge for the calculation — it is part of our trade service.
Related guides & fabrics
Now that you know how to calculate quantity, explore our fabric range or read related guides to make better sourcing decisions.
Send us your measurements. We will do the maths.
WhatsApp your track width, drop measurement, and preferred heading style. Our team at the PJ warehouse calculates fabric quantities for curtain makers every day — no charge, no obligation. Just accurate numbers so you can order with confidence.