Curtain track length calculator
Enter the window width and the fabric, and see the track length that lets the curtains open fully off the glass.
How the length is worked out
When a curtain is open, its fabric gathers into a stack. A sheer stacks to roughly a sixth of the track width, a lined or blackout curtain to about a third. For the glass to be fully clear, the track has to be the window width plus that stack. We solve for the track length that leaves the whole window open.
If a wall, wardrobe or aircon is in the way, the track may need to stop short, and part of the stack will sit over the glass. Our guide to choosing a curtain track covers ceiling and wall fixing.
Common questions
How much wider than the window should a curtain track be?
Wide enough that the curtains stack beside the glass when open. That is usually 15 to 30cm each side for sheers and much more for thick, lined or blackout curtains. The calculator works it out from the fabric.
What is curtain stack?
Stack, or stackback, is the bundle of fabric when the curtains are open. Heavier and fuller curtains stack wider. If the track is not long enough, the stack covers part of the window.
Can I extend the track to the wall?
Yes, running the track wall to wall or into a curtain box is common in HDB and condo living rooms. It hides the stack against the wall and makes the window look wider.
Do I need a double track?
Use a double track if you want a sheer and a night curtain on the same window. Size it for the heavier layer, because that one stacks wider.
More tools
- Instant price estimateAdd your windows and see a price range for curtains and blinds.
- BTO curtain budget plannerPick your flat type and rooms to see a package and total.
- Curtain or blind finderAnswer four questions and get a recommendation for each window.
- Curtain style quizFive picture questions to find your style and a look to copy.
- Blackout or dim-out quizFind out how dark your room needs to be for the way you sleep.
- Curtain fabric quizMatch a fabric to your room, sun, kids, pets and cleaning.
- Sun and glare checkerSee when the sun hits your window through the year in Singapore.
- Curtain width and fabric calculatorPanel width, flat width and fabric to buy for any track.
- Curtain length calculatorThe drop to order for floor, sill or below-sill curtains.
- Blind size calculatorSquare feet per blind, the 20 sq ft minimum and a price range.
- Curtain fabric chartFabric needed by track width, heading and drop.
Tell us about your windows
Send photos and rough window sizes on WhatsApp for an early quote. When you are ready, we measure at your home and bring fabric and blind samples. The visit needs a $50 deposit, credited to your order. Found a lower quote for the same curtains? We price match. See the price match terms.