What curtain width and drop should you order?
Measure the installed pole or track coverage and the drop from the hanging reference used by the chosen heading. Enter the fullness you want and the number of finished panels. Finished-size mode returns flat panel dimensions; sewing mode adds fabric-strip, hem, shrinkage and vertical-repeat calculations.
Should you measure the window or the curtain track?
Use the actual track or pole coverage width rather than the window glass. Finials are not usable hanging width. If additional overlap or returns are not already included in that measurement, enter their combined width separately. Measuring the same allowance twice makes the curtain needlessly wide.
How is fullness converted into panel width?
Combined flat width = (track width + additional overlap/returns) × fullness. Divide by panel count for equal flat panels. A 72 in track at 2× fullness gives 144 in total, or 72 in per panel for a pair. The chosen heading and fabric determine the appropriate fullness; the calculator does not impose a universal ratio.
Combined flat curtain width = (track width + overlap/returns) × fullness; panel width = total ÷ panels; finished drop = measured drop − clearance + puddle
How do clearance and puddle length change the drop?
Finished drop equals measured hanging drop minus clearance plus puddle length. Use clearance when the fabric should finish above the measured endpoint, and puddle length when it should extend beyond it. The hanging reference differs between heading types, so confirm it before entering the measurement.
What sewing allowances are included?
Sewing mode adjusts flat width and finished drop for the expected shrinkage, then adds the entered side, header and bottom allowances. Shrinkage is a percentage loss in the relevant length. The worksheet uses the same percentage in both directions; fabric that shrinks differently across and along the roll needs separate sewing planning.
How does fabric width affect joined curtain panels?
The worksheet estimates full fabric widths required for each equal panel. Side hem allowance is conservatively deducted from each full strip, which can overstate fabric when strips are joined. It does not optimize partial strips, lining or seam allowances. Review the actual panel construction before cutting.
How is a vertical pattern repeat rounded?
The raw strip length is rounded up to a whole vertical repeat, then multiplied by widths and panel count. A purchase-length increment can round the final roll length again. Horizontal repeat and matching between separate windows are not modeled. Optional price is per yard even when the result also shows meters.
Which input units and assumptions should you check?
Use the labeled units and measured project values. Optional fields remain blank unless their data are available; paired fields must be entered together. Fullness is chosen for your heading and fabric. Sewing uses equal panels, repeated full-width fabric strips and entered shrinkage; horizontal pattern matching and lining are separate.
| Input | Unit basis | When used |
|---|---|---|
| Installed rod / track coverage width | in / cm | all modes |
| Measured hanging drop | in / cm | all modes |
| Chosen fabric fullness multiplier | as labeled | all modes |
| Number of finished curtain panels | as labeled | all modes |
| Additional combined overlap / returns (optional) | in / cm | all modes |
| Clearance above measured end (optional) | in / cm | all modes |
| Extra puddle length (optional) | in / cm | all modes |
| Usable fabric roll width | in / cm | mode:sew |
| Side hem allowance per panel edge (optional) | in / cm | mode:sew |
| Header allowance (optional) | in / cm | mode:sew |
| Bottom hem allowance (optional) | in / cm | mode:sew |
| Vertical pattern repeat (optional) | in / cm | mode:sew |
| Expected fabric shrinkage (%) (optional) | as labeled | mode:sew |
| Purchase-length increment (optional) | ft / m | mode:sew |
| Fabric price per yard (optional) | as labeled | mode:sew |
How can you compare and save different scenarios?
Calculate and save a baseline to comparison, change one input and calculate again. Review the itemized results before transferring values. Copy or share the result, download the input and result sheet, or print the worksheet. Clear changes removes the current inputs and results, and refresh starts clean.
Which related calculators help with the next step?
Use Tablecloth Size Calculator and Square Footage Calculator. Check that the measurement units and scope match before using a result as an input elsewhere.
