Use our curtain fabric calculator to work out how many metres of fabric you need. Enter your track or pole width, your finished curtain length and the pattern repeat, and it does the rest, allowing for fullness, hems, heading and pattern matching. If you'd rather work it out by hand, the method is below.

Quick answer: multiply your track width by the fullness for your heading style, then divide by the fabric width (137cm) to find how many widths you need. Add 30cm to your finished length and round up to a whole number of pattern repeats to get each cut length. Multiply the widths by the cut length, then add one pattern repeat for placing the pattern.

How to Work Out Curtain Fabric

1. Measure your track or pole

Measure the full length of the track or pole, not the window. For a pole, measure between the finials. For the best look, the track or pole should extend 15–20cm beyond each side of the window, so the curtains can stack back clear of the glass.

2. Decide your finished length

Measure from the top of the track, or from the pole, to where you want your curtains to end:

• Sill length: about 1cm above the sill
• Below sill: about 15cm below the sill
• Floor length: about 1cm above the floor

3. Choose your heading style

The heading decides how gathered your curtains will be. This is called fullness: how many times wider the fabric is than the track.

4. Work out the number of widths

Multiply your track width by the fullness, then divide by the usable fabric width of 137cm. Round up to a whole number. This is how many widths of fabric you need. For a pair of curtains, the widths are shared between the two, so each curtain may have one and a half widths.

5. Work out the cut length

Add 30cm to your finished length for the hem and heading. Then round up to a whole number of pattern repeats, so the pattern matches across every width. You'll find the pattern repeat on each fabric's product page.

6. Work out the total

Multiply the number of widths by the cut length. Then add one pattern repeat, so the design can sit exactly where you want it at the top of your curtains. Round up to the next whole metre.

Worked Example

A pair of eyelet curtains on a 200cm pole, with a finished length of 150cm, in a fabric with a 64cm pattern repeat:

• Widths: 200cm × 2 = 400cm. 400 ÷ 137 = 2.92, rounded up to 3 widths (1½ per curtain)
• Cut length: 150cm + 30cm = 180cm. 180 ÷ 64 = 2.81, rounded up to 3 repeats = 192cm
• Total: 3 × 192cm = 576cm, plus one 64cm repeat = 640cm
• Fabric to order: 7 metres

Curtain Fabric Calculator FAQs

How much fabric do I need for eyelet curtains?

Eyelet curtains need twice the width of your pole. Multiply your pole width by 2, divide by 137cm and round up to find the number of widths. Then multiply by your cut length: the finished length plus 30cm, rounded up to the pattern repeat.

How much fabric do I need for pencil pleat curtains?

Pencil pleat curtains also use 2 × the track width. If you'd like a fuller, more luxurious gather, a curtain maker may suggest up to 2.5 times.

How much fabric do I need for pinch pleat curtains?

Double pinch pleats use about 2.25 × the track width, and triple pinch pleats about 2.5 ×, as the deeper pleats take up more fabric.

Why does the pattern repeat add to the fabric I need?

Each cut length is rounded up to a whole number of pattern repeats, so the design lines up across every width and both curtains of a pair match. Larger repeats can mean more fabric, but they're also what give bold designs their impact at the window.

Is a curtain fabric calculator the same as a curtain fabric estimator?

Yes, they're two names for the same thing. Both work out how much fabric your curtains need from your track width, curtain length, heading style and pattern repeat.

Does the calculator include lining?

No. The calculator works out your main curtain fabric. Lining usually needs the same number of widths, but as it's plain, there's no pattern repeat to allow for.

My curtain maker has given me a different figure. Which should I use?

Use your curtain maker's figure. Every maker has their own allowances for hems, headings and finishes, so if you're using a curtain maker, check the quantity with them before ordering.

Can Becca Who fabrics be used for curtains?

Yes. Our designer velvets are beautiful for curtains and Roman blinds as well as upholstery, with a rich drape and colours that come alive at the window. A flame retardant (FR) finish can be selected when ordering. Explore our Designer Curtain Fabric collection.

How should I order my curtain fabric?

Order all the fabric for your curtains together, so it's printed in the same run. Our fabric is made to order in the UK and dispatched within 12 working days. If you're unsure of a colour, order samples from any fabric page first to see it in your own light.