Curtain Length Calculator: How to Measure Curtain Drop and Finished Height
How to Measure Curtain Drop for Sill-Length Curtains
For sill-length curtains, measure from the curtain track or pole position down to the window sill. You can also review our curtain measurement instructions if you are unsure where to start measuring.
You can finish the curtain just above the sill, at the sill, or slightly below the sill depending on the style you want. Sill-length curtains are often used for smaller windows, kitchens, and practical spaces.
Eyelet, Pinch Pleat and S-Fold Height Differences
Different curtain heading styles can affect how finished curtain height should be measured.
Eyelet curtains usually hang from a pole. Pinch pleat curtains are often measured from the hook position. S-fold or wave curtains are usually measured based on the curtain track and carrier position.
If you are unsure which height to provide, confirm the curtain heading style first before finalising the curtain drop. For more measuring guidance, visit our curtain measurement instructions.
Recommended Floor Clearance: 1–2 cm / 0.4–0.8 inches
For most floor-length custom curtains, a small floor clearance is recommended.
A clearance of about 1–2 cm, or 0.4–0.8 inches, helps the curtain hang cleanly without touching the floor too much. This also makes daily use, cleaning, and opening or closing easier.
How to Convert Inches to Centimetres for Curtain Length
If your measurement is in inches, you can convert it to centimetres using this simple formula:
1 inch = 2.54 cm
For example, a curtain drop of 90 inches is about 228.6 cm. You can also check this inches to centimetres conversion reference if you need a quick conversion.
Use a Curtain Length Calculator to Estimate Finished Size
Once you know your curtain width and drop, you can use our curtain pricing calculator to estimate the finished size and custom curtain cost.
You can also check our curtain measurement instructions for more detailed measuring guidance before placing an order.
Submit Your Measurements for a Custom Quote
If you are not sure how to measure curtain length, you can send us your window size, track position, room photo, or project details.
For custom sizes, designer projects, trade orders, or bulk curtain enquiries, you can submit a custom size enquiry and we will help review your measurements.
Using a curtain length calculator before ordering helps reduce measuring mistakes and makes it easier to confirm the right finished curtain height for your space.