Feet (ft) and Inches (in) Calculator

An easy to use online feet and inches calculator is presented. It can perform all 4 basic operations (+ , - , , ) on two quantities given in feet and inches. Some examples and problems that may be solved with the help of this calculator are suggested.
The results for the addition and subtraction are given in feet and inches. The result for the mutliplication is given in ft^2, in^2, cm^2, m^2 and yd^2.


Conversion Formula [1]

1 inch = 2.54 centimeters.
1 foot = 12 inches = 12 2.54 centimeters = 30.48 centimeters
1 yard = 3 feet = 36 inches
1 cm = ( 1 / 2.54 ) inch
1 cm = ( 1 / 30.48 ) feet

Symbols for feet and inches
1 " = 1 in
1' = 1 foot


Examples

Example 1 - What is the perimeter of a rectangular garden of length L = 12'3" and width W = 8'11"
The perimeter P is given by
P = 2 L + 2 W = 2 12'3" + 2 8'11"
Multiply
P = 24'6" + 16'22"
Add feet together and inches together
P = 40'28"
Covert 28" into feet
28" = 2 12 + 4" = 2'4"
Add 40' to 2'4" to find
P = 42'4"



Example 2 - Find the area of a rectangular room of length L = 10'4" and width W = 8'5" in in^2 and cm^2
The area A is given by
A = L W
Convert L and W into inches; knowing that 1 foot = 12 inches.
L = 10 12 + 4 = 124 in
W = 8 12 + 5 = 101 in
A = 124 in 101 in = 12524 in^2
Knowing that 1 in = 2.54 cm, A may be converted to cm^2 as follows
1 in^2 = 1 in 1 in = 2.54 cm & 2.54 cm = 6.4516 cm^2
Hence A in cm^2 is given by
A = 12524 in^2 = 12524 6.4516 cm^2 = 80799.84 cm^2



Use of Feet and Inches Calculator

Enter A and B in feet (ft) and inches (in) then select the operation to perform and calculate.

Decimal Places

A = ft     in


B = ft     in
   

Results
     



Problems Involving Operations on feet and inches

Problem 1
A piece of material of length 123 ft 8 in is to be cut into smaller pieces of equal lengths and each piece has a length of 3 ft 6 in. What is the maximum number of pieces that can be made?

Solution
Convert the length L1 of the material into inches knowing that 1 feet = 12 inches
L1 = 123 ft 8 in = 123 12 in + 8 in = 1484 in
Convert the length L2 of the smaller pieces
L2 = 3 ft 6 in = 3 12 + 6 = 42
The number N of smaller pieces that can be made is given by
N = L1 / L2 = 1484 / 42 = 35.3333333333
Hence 35 small pieces can be cut from the larger piece of material.



Problem 2
A rectangular indoor swimming pool has a length L of 12 ft 6 in and its width W is 3 ft 10 in shorter than its its length. Find the width W of the swimming pool.

Solution
W = 12 ft 6 in - 3 ft 10 in
Convert 12 ft 6 in and 3 ft 10 in into inches knowing that 1 foot = 12 inches
W = ( 12 12 + 6 ) - ( 3 12 + 10 ) = 104 in
Convert W in feet and inches
W = 8 12 + 8
W = 8'8"




More References and links

  1. www.nist.gove.pdf
  2. Online Calculators
  3. Units Conversion and Calculators
  4. Geometry Calculators