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Window Blind Size Calculator

Estimate recommended blind width and height from window-opening measurements and mount style.

Updated April 12, 2026
Free online tool
Planning and research use

Why this page exists

Blind sizing is easier when the opening measurements turn into a simple inside-mount or outside-mount recommendation instead of a last-minute guess before ordering. This calculator helps visitors estimate a practical blind width and height from window measurements and the mount style selected.

Interactive tool

Run the estimate

Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.

Calculator

Window blind size calculator

Estimate recommended blind width and height from window-opening measurements and the mount type chosen.

Result

35.75 in x 60.00 in

Estimated blind size based on the window opening entered and the mount-style sizing approach selected.

Recommended blind width35.75 in

Recommended blind height60.00 in

Mount typeInside mount

Sizing noteInside-mount estimate uses a small width deduction for easier fit.

36.00 in by 60.00 in is the opening size used for this estimate.
The inside-mount estimate trims the width slightly to about 35.75 inches while keeping the opening height for reference.
Use the estimate as a sizing starting point only, because the product's headrail size, mounting brackets, and manufacturer recommendations can still affect the final order size.

This is a planning estimate only. Manufacturers use different deduction rules, headrail dimensions, and mounting clearances, so confirm the final size with the blind product being ordered.

Planning note

Last updated April 12, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.

How it works

What the calculator is doing

Enter the window opening width and height, then choose inside mount or outside mount.

For inside mount, the calculator uses a small width deduction to allow easier fit.

For outside mount, it adds overlap to the window opening to estimate a wider and taller blind size.

Understanding your result

This is a sizing starting point, not a manufacturer rule. Final blind size can vary by product line, headrail style, bracket clearance, and the brand's recommended deductions or overlaps.

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Examples

Ways people use this tool

Example scenarios help turn a quick estimate into a more useful comparison or planning step.

Check a basic inside-mount order size

A quick width deduction can help reduce sizing mistakes when ordering a simple inside-mount blind.

Plan outside-mount coverage over the opening

Adding overlap makes it easier to estimate coverage for privacy or light blocking.

Compare two mount approaches before ordering

Seeing both mount styles helps when deciding between a flush look and a more covering outside mount.

FAQ

Common questions

Why is the inside-mount blind slightly narrower?

Inside-mount blinds often need a small width deduction so they can fit more easily within the opening.

Why add overlap for outside mount?

Outside-mount blinds usually extend beyond the opening so they can cover more of the window and reduce light gaps.

Should I still check the product specifications?

Yes. Different blind brands and products have their own sizing guidance, so this estimate should be treated as a planning starting point only.

Related tools

Keep comparing

Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.

Home ToolsUpdated April 11, 2026