Window Prices by Size: Size Tiers and United Inches

A bigger window costs more, though not always in step with its size. In Fixr's casement table, a 24-by-36-inch window runs $290 to $480 installed and a 36-by-60-inch window $720 to $1,200 (updated January 30, 2026) ¹: by our arithmetic, two and a half times the window area for about two and a half times the price. Picture windows jump instead: Fixr lists $580 to $1,056 for 33 to 44 square feet and $1,421 to $2,585 for 45 to 55 square feet ³.

The surveys price size in different units, and some companies use a third: the "united inch," the width plus the height in inches ⁵. Knowing which unit a quote uses, and whether your openings are standard or custom sizes, is most of what it takes to compare prices by size.

Size tiers in the cost surveys

The surveys that publish prices by size use different units, so they cannot be lined up row by row. Here is what three of Fixr's type guides report.

Read the rows with their notes. Fixr says the casement figures are average installed costs for standard-size vinyl windows with double-pane glass ¹, and that the sliding figures reflect labor and materials ². The picture table says only that the price depends on materials, glass and labor, so it may not be a full installed price ³. None of the three is a quote for your opening.

Modernize does not publish a size table, but it puts the gap plainly: a small bathroom window might cost half as much as a large custom window for a living room (updated September 22, 2026) ⁶. Its typical range of $700 to $1,400 per window is given as depending on size, features and location ⁶.

For double-hung windows by size, see double-hung window cost. Bay and bow units are priced as assemblies; see bay and bow window cost.

Why price does not rise evenly with size

Three things change as a window grows.

• Glass and frame. Fixr notes that larger windows need more glass and bigger frames ⁷.
• Glass type. Above a certain size, the glass itself may change. One interior storm window maker, Innerglass Window Systems, caps its standard double-strength glass at 25 square feet or 125 united inches and uses thicker laminated or tempered glass, at extra cost, above that ⁴. That is a storm window maker's rule, not a replacement window maker's, but it shows the kind of threshold to ask about. Glass near doors and floors is a separate, code-driven question: see where tempered glass is required.
• Handling. Fixr says larger casement windows need multiple technicians to position and install ¹, and that large second-floor windows may need a crane ⁷. That is labor, not product, which is why window replacement labor cost rises with size too.

Standard vs. custom sizes

A standard size is one a manufacturer lists in its catalog; a custom size is built to your opening. In replacement work the opening is often not a current catalog size, especially in older houses, and Thumbtack describes new windows being custom made to order after an installer measures ⁵. So the practical choice is usually between a made-to-size unit and a standard unit plus carpentry, trim and siding work to fit it. Our standard window sizes article covers size codes, rough openings and what resizing an opening costs.

United inches: how size-based pricing works

A united inch is the window's width plus its height, in inches; Thumbtack says windows are priced by this unit ⁵. A window 36 inches wide and 48 inches tall is 84 united inches. The unit is a sum, not an area, so it grows more slowly than square footage as a window gets bigger: a 72-by-48-inch window has twice the area of the 36-by-48 one but only about 43% more united inches (120), by our arithmetic ⁵.

The Innerglass order form above shows two details worth asking about, whatever kind of window is being priced ⁴:

• Rounding. It asks for each measurement rounded to the nearest whole inch before adding. Other companies may round differently.
• Mulled windows. For an opening built as two windows with a mullion between them, it adds the width and height of each window separately, because the opening is two windows. A twin window can come to more united inches than one window of the same overall size.

A price list may also group sizes into bands, so every window up to a set number of united inches carries one price. When an advertised price is "starting at" a figure, ask what size it applies to.

How to use size when comparing quotes

• List every opening. Note the type, the width and height you measured, and the room. How installers measure for replacement windows shows where to measure.
• Ask how size is priced. Per window, per size band, per united inch or per square foot? A quote in one unit cannot be compared to another until you convert.
• Ask whether each size is standard or custom, and whether any resizing, trim or siding work is in the price.
• Ask about glass changes. Does any window cross a size where the glass type changes?

Size is one driver among several. Frame material, glass package and installation method are covered in the window replacement cost guide, and line-by-line quote checks in how to compare window quotes. When you know your sizes, you can compare quotes from window installers.

We are not affiliated with the manufacturers named.

About these figures

• ¹ Reported: Fixr casement table of average installed costs by size for standard-size vinyl double-pane windows ($290 to $480 for 24 x 36 inches up to $720 to $1,200 for 36 x 60 inches) and its note on multiple technicians for large units, updated January 30, 2026, checked October 26, 2026. The area-to-price comparison is our own arithmetic.
• ² Reported: Fixr sliding window cost by size in square feet, labor and materials included, updated January 31, 2025, checked October 26, 2026.
• ³ Reported: Fixr picture window cost by size in square feet, updated January 31, 2025, checked October 26, 2026.
• ⁴ Reported: Innerglass Window Systems interior storm window order form (revision 15, effective June 15, 2023): the 25 square foot or 125 united inch limit for double-strength glass, rounding to the nearest inch and the rule for mulled openings, checked October 26, 2026.
• ⁵ Reported: Thumbtack definition of a united inch, pricing by united inch and custom made-to-order windows, updated October 19, 2026, checked October 26, 2026. The 72 x 48 comparison is our own arithmetic.
• ⁶ Reported: Modernize typical range of $700 to $1,400 per window and its small-versus-large window comparison, updated September 22, 2026, checked October 26, 2026.
• ⁷ Reported: Fixr notes that larger windows need more glass and bigger frames and that large second-floor windows may need a crane, updated January 21, 2026, checked October 26, 2026.