The metric system is not the only one used in the world, there is also the imperial system of units, of which the foot is one of the units of length: it is divided into 12 inches, another unit of the same system. Concretely, it is therefore very simple to convert feet into inches, since it suffices to multiply the first ones by 12. However, if you do not have a whole number of feet, the principle remains the same: you multiply the number of feet by 12, to which you add the number of inches to get your final measurement.
Method 1 of 2: Convert whole feet to inches
Step 1. Write down your whole number of feet on a sheet of paper
Converting feet to inches couldn't be easier. Start by entering the measurement with its unit, the foot. Usually, after a digit, you should put the unit in its short form, namely "pi" or "’ ".
- As is often the case in mathematics, let's take a concrete example, that of a section of wall that you measured with a tape. You found it to be eight feet long. Write this measurement on your sheet of paper as follows:
Step 8. or better 8 ft or 8’
Step 2. Multiply this number of feet by 12
Since a foot is divided into 12 inches, to convert feet to inches you must multiply the measurement made or given by 12.
- Let's take the example of the wall. You have entered 8 feet, enter following × 12, then do the operation, which gives the following equality:
- 8 ft × 12 = 96 (with "pi" for feet)
Step 3. Put a unit to your answer
By dint of doing calculations, we would forget the units. Here, multiplication done, do not forget to put "inches", "in" or "" ". If you don't put anything in, someone reading you won't know what you're talking about and in school, as part of an exercise, you will lose points.
- In the example taken, you should write as follows:
- 8 ft × 12 = 96 po or 96 ″
Step 4. To iron from inches to feet, divide by twelve
You can switch from one unit to another, it's not complicated, just reverse the operation. To get inches, multiply by 12, and to get feet, divide by 12. Of course, you also need to change the unit.
- If we take the last one and want to get back to the feet, just divide by 12:
- 96 in ÷ 12 = 96 in × 1/12 = 8 ft
Method 2 of 2: Convert only feet and inches to inches
Step 1. Enter the number of feet
Not all measurements, however much, fall on a whole number of feet. When you measure, you often get a measurement in so many feet and so many inches. Say, in a multiplication and division exercise, you are given a measurement in x feet and y inches. Do not panic ! Start by entering only the number of feet, ignore the number of inches for now.
- Take the example of someone whose height is five feet and three inches. In an exercise, you are asked to convert this height to inches. Write down the number of feet first, as follows:
- 5 feet (5 ft or 5 ′)
Step 2. Multiply the number of feet by 12
You see, it starts exactly like in the previous part. You multiply by 12 and you get a result in inches.
- Let's go back to our example of size. Complete your first mention:
- 5 ft × 12 = 60 in
Step 3. Add the remaining inches
Now is the time to add the inches that were previously left out: the calculations are complete, all that remains is to put the unit, namely inches.
- Let's go back to our example of size. Complete your calculations by adding the remaining inches, which gives:
- 5 ft × 12 = 60 in + 3 '' = 63 ''
Step 4. Do the reverse calculation
You may also be asked, from a measurement entirely in inches, to convert it to feet and inches. You have to start by dividing your number of inches by 12 to have feet and if your division leaves you with a remainder, this will be the number of inches to add to the feet found. So, if a division gives a result of 4 with a remainder of 5, your answer will be: 4 ′ and 5 ″ (4 ′ 5 ″).
- The remainder of a division is the number that cannot be divided by the divisor. Thus, if you divide 12 by 4, there is no remainder, because 12 divides exactly by 4 to give 3. On the other hand, dividing 12 by 5 does not give a whole number, because there goes 2 times (2 x 5 = 10), but there is a remainder of 2 (result of 12 -10) which cannot be divided by 5 without having to put a comma in the quotient.
- Let's go back to our example. To regain feet, it is necessary to operate as follows:
- 63 in / 12 = 5 (and there are 3 left). The answer is 5'3 ''
- To switch from inches to feet, it is also sufficient, another method to multiply the first by 0, 08333.
- What you have done with feet, you can also do with yards ("yards"), another Anglo-Saxon unit of measurement. Since there are three feet in a yard, to get inches you must first multiply the yards by three to get feet and then by twelve to get inches.