Guide
United-inch pricing for windows, explained
United inches (u.i.) are a window's width plus its height, in inches. Many installers and suppliers price replacement windows at a rate per united inch, because it takes two measurements and one multiplication.
How to calculate united inches
Add the width and the height. A window 36 inches wide and 48 inches high is 36 + 48 = 84 u.i.
United inches are half of a window's perimeter. They are not its area. A 24″ × 60″ window and a 42″ × 42″ window are both 84 u.i., but the second has 22.5% more glass (1,764 square inches against 1,440).
Fractions of an inch
Few openings measure a whole number of inches, so you need a rounding rule. Pick one and use it on every opening. Quote for Windows rounds each side to the nearest inch and then adds them, so 35½″ × 47¾″ is priced as 36 + 48 = 84 u.i.
How the price is worked out
Price = united inches × rate per united inch
The rates below are examples, not a price list.
| Opening | Size | United inches | Rate | Line price |
|---|---|---|---|---|
| Kitchen North, casement | 48″ × 48″ | 96 | $14 | $1,344 |
| Living room, bay | 48″ × 36″ | 84 | $22 | $1,848 |
The bay has fewer united inches than the casement and still costs more. The rate belongs to the product, so a casement, a bay and a patio door each carry their own.
Minimum prices
A small window can price out below what it costs you to supply and fit. That is why many installers set a minimum price per product.
With an example rate of $10 per u.i. and a $450 minimum:
- 24″ × 30″ is 54 u.i. × $10 = $540. That is above the minimum, so the line is $540.
- 18″ × 24″ is 42 u.i. × $10 = $420. That is below the minimum, so the line is $450.
What the base price leaves out
A rate per united inch gives you a base price. Colour, glass and other upgrades are added to it. An upgrade can be priced three ways. Here is each one on the casement above, which is 96 u.i. with a base of $1,344:
- A flat amount. $75 adds $75.
- A rate per united inch. $2 per u.i. adds 96 × $2 = $192.
- A percentage of the base. 10% adds $134.40.
Installation and disposal are usually their own lines under the windows, so the customer sees what each part costs. Sales tax goes on after that. See sales tax and deposits on a quote in Canada.
Doors work the same way
If you price patio doors and entry doors by united inch, the method is identical: width plus height, times your rate.
Let the software do the arithmetic
Quote for Windows prices each opening as you add it, using the rate and minimum price you set for each product in your own catalogue. You can import the catalogue from Excel. Upgrades can be flat, per united inch or a percentage, and they are added after the minimum is applied.
It is free during the beta. See the features or what it costs.
Questions
What does u.i. stand for?
United inches: the width plus the height of the window, in inches.
Is a united inch the same as square footage?
No. United inches add two sides. Square footage multiplies them. Two windows with the same united inches can have different areas.
How many united inches is a 36″ × 48″ window?
84. That is 36 + 48.
Do I need a minimum price?
It isn't required, but small openings can fall below your cost without one. A minimum per product keeps them profitable.