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Curtain Fabric Calculator - Curtain Fabric Estimator
Work out how many metres of fabric you need from track width, drop, fabric width, pattern repeat, and fullness.
Calculate curtain fabric in seconds
Use the calculator below, then read the simple method and examples further down if you want to check the maths.
Note: This calculator uses standard assumptions (including hem allowance and rounding up to full widths). Curtain makers may use different allowances. If you are unsure, email us and we will double-check before you order.
How to calculate curtain fabric
If you want to sense-check the calculator, this is the standard method. Always round up, not down.
1) Work out the number of fabric widths
Multiply your track width by your chosen fullness, then divide by the fabric width.
Formula
Widths required = (Track width × Fullness) ÷ Fabric width
Round up to the next whole width.
Example
Track width 200cm, fabric width 137cm, fullness 2.0:
(200 × 2.0) ÷ 137 = 2.92 → round up to 3 widths (1.5 widths per curtain on a pair).
2) Work out the cut drop (plain or patterned)
Add hem allowance to your finished drop. If the fabric has a vertical pattern repeat, round up to the next full repeat.
Plain fabric
Cut drop = Finished drop + hem allowance
Patterned fabric
Cut drop = (ceil((Finished drop + hem allowance) ÷ Pattern repeat) × Pattern repeat)
Example
Finished drop 150cm, hem allowance 30cm = 180cm. Pattern repeat 25cm:
180 ÷ 25 = 7.2 → round up to 8 repeats → 8 × 25 = 200cm cut drop.
3) Total fabric required (metres)
Multiply the number of widths by the cut drop, then convert cm to metres.
Formula
Total fabric (cm) = Widths required × Cut drop
Total fabric (m) = Total fabric (cm) ÷ 100
Example
3 widths × 200cm cut drop = 600cm = 6.0 metres.
Curtain fabric calculator FAQs
What fullness should I use for curtains?
As a guide, pencil pleat and eyelet often use around 2.0x fullness. Pinch pleat is commonly 2.5x. Wave headings vary by system and spacing. Use the fullness guide above if you are unsure.
How do I calculate curtain fabric with pattern repeat?
Add your hem allowance to the finished drop, divide by the vertical pattern repeat, round up to the next whole repeat, then multiply back by the repeat. This ensures the pattern matches across drops.
Why does the calculator round up?
Curtain making requires whole fabric widths and full pattern repeats. Rounding down risks ordering short, which can stop you making the curtains properly.
Does fabric width matter?
Yes. Many curtain fabrics are around 137cm wide, but some (including certain velvets and specialist fabrics) vary. Using the correct fabric width changes the number of widths required.
Can you check my fabric calculation before I order?
Yes. Send your track width, drop, fabric width, pattern repeat and heading type, and we will sense-check the calculation.
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