Curtain Size Calculator

Curtain buying decision tool

Curtain Size Calculator

Measure your window, choose a curtain scenario, and get the panel size, rod width, and buying checklist before you shop.

Calculate my curtain size Browse common sizes
  • Free calculator
  • Inches or centimeters
  • Ready-made panel lengths

Choose a curtain scenario

Start with the room or buying situation, then fine-tune the measurements.

Core measurements

Start with the window size. Adjust advanced details only if you need a specific curtain style.

Measure the window opening in inches.
Use the glass or frame height as your base.
Leave blank to calculate a suggested panel width.
Advanced curtain details
Blackout bedroom curtains Size bedroom blackout panels
Sliding glass door curtains Measure wide door curtains
Sheer linen curtains Choose soft layered fullness
Thermal curtains for winter Estimate fuller coverage
Renter-friendly curtain rods Plan rod height and width
Privacy curtains vs blinds Compare mount options

Common Curtain Size Chart

These examples assume outside-mount curtains with standard 2x fullness. Use them as a quick check, then use the calculator above for your exact window height, mount type, and panel width.

Window width Total curtain width Common panel setup Typical ready-made lengths
36 in 72 in 2 panels around 36-42 in wide 63, 84, or 96 in
48 in 96 in 2 panels around 50-52 in wide 84 or 96 in
60 in 120 in 2 panels around 54-60 in wide 84, 96, or 108 in
72 in 144 in 2 panels around 72 in wide or 4 narrower panels 84, 96, or 108 in

Curtain Fullness Quick Guide

Light, 1.5x

Works for simple coverage, tight spaces, or budget panels where a flatter look is acceptable.

Standard, 2x

A reliable starting point for most bedroom, living room, and dining room windows.

Full, 2.5x

Better for blackout panels, wider windows, and rooms where the curtains should look richer.

Extra full, 3x

Useful for sheers and decorative curtains that need soft folds even when stretched across the window.

How to Use This Calculator

  1. Measure the window width and height in inches or centimeters.
  2. Choose a scenario preset such as bedroom, blackout, sheer, or sliding glass door.
  3. Pick inside mount only when the curtain will sit within the frame; otherwise use outside mount.
  4. Enter a known panel width if you already have a product in mind.
  5. Use the buying recommendation to compare panel count, width, length, and rod size.

Frequently Asked Questions

How wide should curtains be?

For most windows, total curtain fabric width should be about 2 times the window width. Use more fullness for sheers and a fuller look, or slightly less for simple coverage.

Should I measure the window or the curtain rod?

Start with the window opening. For outside mounts, add rod width beyond both sides of the frame so the panels can cover the window and stack back cleanly.

What length curtains should I buy?

Measure from the rod position to the finished drop. The calculator recommends the next common ready-made length, such as 84, 96, 108, or 120 inches.

How many curtain panels do I need?

If you know the panel width, divide the total curtain width by that panel width and round up. If not, two panels is a common starting point for standard windows.

Popular Curtain Measurement Guides

Curtain Size Chart

Compare common window widths with typical curtain width and length choices.