Blinds: Price Per Square Foot With Minimum Billing

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Custom blinds and shades are usually priced by the square foot with a minimum billable size, so a tiny window still pays for the setup. This recipe converts inches to square feet, applies the minimum with MAX and multiplies by the rate.

Quick formula: Larger of the minimum and actual square feet, times the rate:

=ROUND(MAX(D2,B2*C2/144)*E2,2)

A 36 x 48 inch blind is 12 sq ft; at $9.50 per sq ft with a 12 sq ft minimum it costs $114.00.

Functions used (tap for the full reference guide):

MAX ROUND

The example

Three windows. The small one is billed at the 12 sq ft minimum, not its true 6 sq ft.

	A	B	C	D	E	F	G
1	Case	Width in	Height in	Min sq ft	Rate/sq ft	Price	Billable sq ft
2	Standard window	36	48	12	$9.50	$114.00	12.0
3	Small window	24	36	12	$11.00	$132.00	12.0
4	Patio door	60	72	12	$8.00	$240.00	30.0

The formula

Area in square feet, floored at the minimum, times the rate:

=ROUND(MAX(D2,B2*C2/144)*E2,2) // price; billable sq ft = MAX(MinSqFt, Width*Height/144)

How it works

Here is the logic, one piece at a time:

B2*C2/144 converts square inches to square feet because there are 144 in a square foot.
MAX(D2, ...) picks the larger of the minimum and the actual area.
Multiplying by the rate in E2 gives the dollars.
ROUND(...,2) rounds to cents.

Always measure width and height to the nearest eighth and round up to the supplier's size increments.

Try it: interactive demo

Interactive

Enter the size in inches, the minimum square feet and the rate.

Width (inches)

Height (inches)

Minimum sq ft

Rate per sq ft ($)

Variations

Round the size up to whole inches

Many suppliers price in whole-inch steps.

=ROUND(MAX(D2,ROUNDUP(B2,0)*ROUNDUP(C2,0)/144)*E2,2)

Add a motorization fee

Add a flat upcharge for motors.

=ROUND(MAX(D2,B2*C2/144)*E2,2)+MotorFee

Pitfalls & errors

Inside and outside mounts use different measuring rules; see the inside mount deduction recipe.

Dividing by 12 instead of 144 gives the wrong area by a factor of twelve.

Show the customer the billable area when it is the minimum so the price is not a surprise.

Practice workbook

📊

Download the free Blinds: Price Per Square Foot With Minimum Billing practice workbook

Edit the yellow size, minimum and rate cells; price and billable area recalculate.

Frequently asked questions

Why a minimum size?

Small blinds take nearly as long to make and ship as large ones.

Does it work for shades with fabric repeats?

Add a fabric adjustment factor to the rate cell if your supplier charges one.

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Function references: MAX ROUND