Curtain Size Lab Search

SIZES GUIDE · REVIEWED SEPTEMBER 11, 2026

How to Measure Windows for Curtains

Measure a window, working rod or track, side extension, heading reference, finished drop, fullness, and panel count in the right order.

MEASURED WIDTHFINISHED DROP
Original proportional diagram. Use actual measurements; drawing is not to scale for a specific product.

SHORT ANSWER

Start here

Record the window-frame width and height, the working rod or track width excluding finials, the hanging reference for the chosen heading, and the drop to your desired endpoint. Keep these as separate measurements; do not convert the window opening directly into a product size without fullness and hardware context.

Measure withRigid metal tape
Rod widthExclude finials
DropUse heading reference
VerificationMeasure twice

How to measure

  1. 01

    Measure the actual working rod or track width; if hardware is not installed, record the window-frame width and your planned side extensions separately.

  2. 02

    Measure the drop from the reference point stated for the selected heading—not from an unrelated edge of the window.

  3. 03

    Check whether a package contains one panel or a pair, then compare total flat fabric width rather than the label width alone.

  4. 04

    Recheck the selected product, tape, hooks, carriers, and fabric before ordering or cutting.

MEASURE, CALCULATE, VERIFY

Turn the window measurements into a curtain plan

Work through the calculator with the measurements you just took. It keeps rod span, fullness, panel width, and finished length together so one choice does not contradict another.

CURTAIN SIZE CALCULATOR

What are you measuring?

Desired curtain endpoint
72 in rod
Required total flat width144 in total

72 in flat width per panel × 2

Finished length84 in
Suggested rod72 in

Uses your 2× fullness and 6 in side extension. Finished length is the measured hanging-point-to-endpoint value you entered.

Open the detailed calculator

MULTI-WINDOW PROJECT

Keep every window in one quantity sheet

Saved only in this browser unless you export the JSON file. Browser storage can be cleared and is not a backup.

Add a measured window to begin the project sheet.

Choose the finished width

Start with the planned rod span, then apply the fullness you want. The calculator divides the total across your panel count.

Check width and fullness

Choose the endpoint

Measure from the actual hanging point to the sill, below-sill point, or floor endpoint you intend to use.

Check finished length

Confirm the product

Compare the calculated dimensions with the seller’s stated panel width, length, header, and package quantity.

Check panel count

BEFORE ORDERING

Recheck the actual window, the intended hanging point, and the selected product page. Header take-up, product tolerances, pattern matching, and fabric behavior can change the finished result.

WORKED CALCULATION

Window-to-curtain example

Window-frame width
60 in (152.4 cm)
Side extension
6 in each side
Fullness
2×
Formula(60 in + 6 in + 6 in) × 2

144 in (365.8 cm) total flat curtain width

Measure the finished drop separately from the chosen attachment point. This example is not an installation specification.

Recalculate with your measurements

Measure the window before choosing a product

Record the outside frame width and height as reference dimensions. Then record available wall space, sill projection, nearby furniture, and the intended curtain endpoint separately.

Turn window width into working rod width

If hardware is not installed, add the chosen left and right extension to the frame width. Published examples vary, so keep both sides editable. If hardware is installed, measure the usable span and exclude decorative finials.

Turn working width into curtain width

Multiply the usable rod or track width by the appropriate heading fullness. Add all panel widths together and check whether the package contains one panel or a pair.

Measure drop from the attachment point

Use the ring eye, clip, grommet top, pocket top, pleat hook, or track carrier specified for the product. Measure to the chosen sill, apron, floor-clearance, break, or puddle endpoint and record the choice.

Write down every assumption

Keep units, endpoint, panel count, fullness, heading, product identifier, and package quantity with the measurements. Finished sizes, header take-up, hardware geometry, and manufacturer tolerances vary.

Before you order or cut

Measure the actual window and selected product. Finished sizes, fullness, header take-up, hardware geometry, and manufacturer tolerances vary. Fabric can shrink, stretch, or behave differently by composition. Measurements do not guarantee fit, privacy, water containment, installation, load capacity, or structural safety. Use the selected product instructions, and have a professional workroom verify expensive custom-fabric orders.

SOURCE NOTES

What this page is based on

Measurements here combine mathematical results with labeled commercial conventions and design recommendations. Disagreements are kept as ranges rather than averaged into a false standard.

  1. BETYDLIG/RÄCKA/HUGAD buying guide — Measure your windowIKEA · reviewed 2026-09-11

    Primary manufacturer guide: add at least 6 in each side, add 6 in above, and use 2–2.5× rod width for panel planning.

  2. VIDGA — How to measure your windowsIKEA · reviewed 2026-09-11

    Current manufacturer track-system guide with measured-window diagrams, minimum side extension, stack-back planning, and hanging-point length references.

  3. Buying curtainsJohn Lewis & Partners · reviewed 2026-09-11

    Retailer/workroom guidance on pole extension, hanging references, sill/floor endpoints, ready-made metric ranges, and double fullness.