Curtain Fabric Calculator
Build a curtain yardage estimate from the opening size, finished drop, panel count, fullness, fabric width, and construction choices. The result is a planning figure, so you can see the assumptions before ordering cloth.
Select Curtain Style
You have room for more fullness. Each panel needs 64″ and you are already buying 2 full fabric widths for it, leaving 42″ spare. You could go up to 3× fullness without buying any more fabric.
The panel geometry assumes a flawless cut and a dead-square drop. This adds room for levelling a hem, a flaw in the cloth, or a mis-cut.
Combined planning total
12.5yards
11.5 yards of main fabric per window
Use the purchase quantity below when ordering your main fabric.
- Rod Pocket curtains for 1 window.
- Window: 48″ wide × 84″ drop - outside mount.
- 2× fullness = 122″ total fabric width.
- 2 fabric widths per panel (seamed).
- Each panel needs 64″ and you are buying 106″ of width for it, leaving 42″ spare.
- Fullness could go up to 3× at no extra fabric cost: the panel still fits inside the widths already being bought.
- Yardage moves in steps, not smoothly. It only changes when a panel needs another whole fabric width, so raising fullness inside a step is free and raising it past one costs a full width.
- Cut length: 102″ (drop 84″ + header 6″ + hem 8″ + 4″ overlap).
- DIY profile adds a 10% cutting allowance (1.13 yd) to the 11.33 yd the panels themselves need.
What the Calculator Does With Your Measurements
Curtain yardage changes in jumps. A panel that is slightly wider than one usable fabric width needs a second full drop seamed to it. This calculator shows that joined-width step instead of treating the project as one large rectangle.
You choose the panel count
The gathered width is divided among one, two, or three panels per window. The calculator does not decide the panel arrangement for you.
It allows for joined widths
One inch is removed from the entered bolt width. Each panel is then rounded up to the number of those usable widths it needs.
Header allowances are fixed
The selected style adds a built-in header allowance from 4 to 10 inches. Your fullness choice remains separate and does not change with the style.
Extra materials stay visible
Lining, valance, and tieback amounts appear as their own lines. Read the breakdown before treating the grand total as an amount of one fabric.
The Live Curtain Method, Step by Step
These are the rules used by the calculator above. They are useful when you want to trace a result or compare it with a workroom plan.
1. Work out the width to cover
For an inside mount, the model starts with the entered window width. For an outside mount, it adds 6 inches plus two times the entered rod return depth. That modeled width is multiplied by the selected fullness, then divided by the number of panels per window.
2. Find the joined widths for each panel
The side-turn allowance is added to both edges of every panel. The calculator treats the usable fabric width as the entered bolt width minus 1 inch. It divides the panel cut width by that usable width and rounds up to a whole number of fabric widths. Do not subtract the inch yourself before entering the fabric width.
3. Build the cut length
Main-fabric cut length starts with the finished drop. It adds your bottom hem, a fixed allowance for the chosen header, and 4 inches when outside mount is selected. Rod pocket adds 6 inches; tab top and pencil pleat add 8 inches; grommet and ripple fold add 4 inches; pinch pleat and goblet add 10 inches. If you enter a vertical repeat, the whole cut length is rounded up to the next repeat.
4. Convert the drops to yardage
Cut length is multiplied by the joined widths per panel, the panel count, and the number of identical windows. The inch total is divided by 36, then the purchase figure is rounded up to the next quarter yard. Optional materials are calculated separately and added to the displayed grand total.
A Result You Can Reproduce
Leave the calculator at its starting settings: one 48-inch-wide window, an 84-inch finished drop, outside mount, two rod-pocket panels, 2× fullness, 54-inch fabric, a 3.5-inch return, 1.5-inch side turns, an 8-inch hem, no pattern repeat, and no extras.
- The modeled outside width is 48 + 6 + (2 × 3.5), which is 61 inches.
- At 2× fullness, 61 inches becomes 122 inches. Dividing that between two panels gives 61 inches per panel.
- Side turns add 3 inches, so each panel is 64 inches wide. A 54-inch bolt gives 53 usable inches in this model, so each panel needs two joined widths.
- Cut length is 84 + 6 for the header + 8 for the hem + 4 for the outside mount, giving 102 inches.
- Two panels × two fabric widths × 102 inches equals 408 linear inches, or 11.33 yards for the panels themselves. The DIY profile adds a 10 percent cutting allowance of 1.13 yards, giving 12.5 yards of main fabric after rounding to the next quarter yard. Switch the allowance to Professional for a tighter layout.
This example follows the software method. A real pattern can call for a different header depth, join placement, or matching plan.
Curtain Yardage Reference
These are live-method outputs for one window with an outside mount, two rod-pocket panels, 2× fullness, 54-inch fabric, a 3.5-inch return, 1.5-inch side turns, an 8-inch hem, no repeat, no lining, no valance, and no tiebacks.
Notice that some widths share the same result. They need the same number of joined fabric widths under these settings. Crossing the next width threshold creates a larger jump.
| Window Opening Width | 63" Finished Drop | 84" Finished Drop | 96" Finished Drop |
|---|---|---|---|
| 36″ | 5 yd | 6.25 yd | 7 yd |
| 48″ | 10 yd | 12.5 yd | 14 yd |
| 60″ | 10 yd | 12.5 yd | 14 yd |
| 72″ | 10 yd | 12.5 yd | 14 yd |
| 96″ | 15 yd | 18.75 yd | 21 yd |
Change any setting and the table no longer applies. Use the calculator for your own panel count, header, mounting method, and cloth.
How Optional Materials Are Handled
Lining
When lining is selected, the model uses the same fullness width as the face fabric, but leaves out the face-fabric side turns. Its cut length is the finished drop plus 4 inches. It uses the face fabric's assumed usable width and does not apply the face fabric's vertical repeat. If your lining has a different bolt width or construction, calculate it from its own cut plan.
Valance
The valance option uses the modeled covered width and chosen fullness. Its cut length is the entered valance drop plus the main hem and the fixed allowance for the selected header. It assumes one valance for each window.
Tiebacks
The tieback line is a rough area allowance based on one 24 by 6 inch tieback for each selected panel, with two layers per tieback. It does not lay out curved shapes, bias strips, interfacing, or decorative ends.
Read the breakdown as a shopping list
Face fabric, lining, and contrast materials may be different products. The grand total is useful for seeing the scale of the project, but it is not automatically the number of yards to order from one bolt.
Checks to Make Before You Order
Confirm the hanging point
Fit or choose the rod, track, rings, and hooks first. Measure the finished drop from the actual hanging point at the left, centre, and right.
Check the heading instructions
Tape, grommet, and track systems can specify their own fullness and header depth. Compare those figures with the calculator's fixed assumptions.
Inspect the real cutting width
The tool always removes 1 inch from the width you enter. Check whether wide selvages, coating, flaws, or a border print leave less room than that.
Plan pattern placement on paper
A vertical repeat only lengthens each main drop. The calculator does not place motifs, match joins, account for a horizontal or half-drop repeat, or choose where the first cut begins. See the pattern repeat guide for the terms to check on the fabric specification.
Test compatible materials
Face fabric and lining should suit the same construction and care plan. Follow the supplier's instructions and test a sample when shrinkage, pressing, light exposure, or drape could affect the finished panels.
Where This Estimate Stops
The calculator is a rectangular joined-width model. It does not draft a curtain pattern or inspect the fabric. It cannot choose seam positions, balance a motif across a pair, model railroaded cloth, allow for a decorative leading edge, or judge whether a bulky fabric will gather as planned.
It also does not add a general allowance for flaws, shrinkage, test cuts, future repairs, or workroom preferences. Add anything extra for a clear reason after reviewing the cut list, rather than applying a percentage by habit.
For expensive fabric, unusual hardware, shaped hems, or a demanding pattern match, take the calculator result to the person making the curtains and confirm the final cut plan before purchase. Our window measuring guide can help you prepare the dimensions for that conversation.
Frequently Asked Questions
Want to inspect the rules used across the site? Read the calculation methodology.
Related Curtain Guides
How Much Fabric for Curtains?
A practical buying guide for curtain projects
How to Measure Windows for Curtains
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What Is Pattern Repeat?
Understand the repeat printed on a fabric listing
Fabric Width Guide
See why usable width changes the layout
Fabric Yardage Chart
Early reference ranges for several project types
Outdoor Fabric Yardage
Questions to check for outdoor cloth
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