KLM Labs

How to calculate square footage from inches and fractions

Multiply the length by the width in inches, then divide by 144: 48" × 96" is 4,608 square inches, or 32 square feet.

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Rooms measured in feet, inches and fractions

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Length	Width	Square inches	Square feet	Square yards	Square meters
12' 6"	10' 3"	18,450	128.13	14.24	11.903
12' 6-1/2"	10' 3-1/4"	18,549.13	128.81	14.31	11.967
11' 9"	13' 2"	22,278	154.71	17.19	14.373
9' 10-3/4"	7' 4-1/2"	10,509.38	72.98	8.11	6.78
15' 3-3/8"	11' 7-5/8"	25,603.73	177.8	19.76	16.519
20' 0"	14' 8"	42,240	293.33	32.59	27.252
7' 11-1/4"	5' 2-3/4"	5,976.94	41.51	4.61	3.856

Square feet and yards to 2 decimal places, square meters to 3.

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Sizes measured in inches, in square feet

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Size (inches)	Square inches	Square feet	Square meters
12 × 12	144	1	0.093
18 × 18	324	2.25	0.209
24 × 24	576	4	0.372
12 × 24	288	2	0.186
30 × 60	1,800	12.5	1.161
36 × 80	2,880	20	1.858
48 × 96	4,608	32	2.973

A square foot is 144 square inches (12" × 12").

Why divide by 144?

A square foot is 12" × 12", or 144 square inches. Dividing by 144 counts how many fit.

What about feet, inches and fractions?

Turn each side into inches first. A 12' 6" × 10' 3" room is 150" × 123" = 18,450 square inches, or 128.13 square feet. With fractions:

12' 6-1/2" is 150.5" and 10' 3-1/4" is 123.25".
150.5 × 123.25 = 18,549.125 square inches.
Divide by 144: 128.81 square feet.

Is 12' 6" the same as 12.6 feet?

No: 12' 6" is 12.5 feet, since 6" is half a foot. Multiplying 12.6 × 10.3 for the 12' 6" × 10' 3" room gives 129.78 square feet instead of 128.13.

Square yards or square meters?

Divide square feet by 9 for square yards, or multiply them by about 0.0929 for square meters. The 12' 6" × 10' 3" room is 14.24 square yards and 11.903 square meters.