How Many Inches Are in a Foot?

Quick answer: There are exactly 12 inches in a foot. This is not an approximate figure. One foot is defined as 12 inches, so 1 foot = 12 inches, 2 feet = 24 inches, and 5 feet = 60 inches.

The exact rule: 1 foot = 12 inches

The foot and the inch belong to the same system, and the link between them is fixed. The symbol for feet is a single prime mark (‘), and the symbol for inches is a double prime mark (“). So a height written as 5’6” means 5 feet and 6 inches, which is 66 inches in total.

The formula is simple: inches = feet x 12. To go the other way, divide inches by 12. For example, 30 inches divided by 12 is 2.5 feet, which is written as 2 feet 6 inches. You can check any value with the feet to inches converter, and if you need metric units, the inches to cm converter will take you from inches to centimetres.

Why 12 inches?

Twelve is a useful number because it divides evenly by 2, 3, 4 and 6. That made it practical for builders, carpenters and tailors long before modern measuring tools, because a foot could be split into halves, thirds and quarters without awkward fractions. A half foot is 6 inches, a third of a foot is 4 inches, and a quarter of a foot is 3 inches.

Today the foot is defined through metric units: one foot is exactly 0.3048 metres, which is the same as 30.48 centimetres. Since one inch is exactly 2.54 centimetres, 12 inches x 2.54 = 30.48 centimetres, so the two definitions agree exactly.

Real-life examples

A standard school ruler is 12 inches long, so it is exactly one foot. A footlong sandwich is made to be about one foot long. Many adult shoes are close to one foot in length, which is a handy reminder of where the unit name comes from, though shoe lengths vary.

• A 12-inch ruler is the clearest everyday example of one foot.
• A kitchen tile is often 12 inches square, so one tile edge is one foot.
• A sheet of paper is shorter than a foot, at 11 inches for US letter paper, which is a useful comparison.
• A person’s height in feet and inches, such as 5 feet 8 inches, is really a count of feet plus leftover inches.

How to convert feet and inches together

Most real measurements are not a whole number of feet. To convert 5 feet 6 inches to inches, first convert the feet, 5 x 12 = 60, then add the 6 inches, giving 66 inches. To convert 66 inches back, divide by 12: 66 / 12 = 5.5 feet, which is 5 feet 6 inches, because 0.5 feet x 12 = 6 inches.

• Always convert the feet part first, then add the remaining inches.
• Keep the remainder under 12, otherwise you have another whole foot.
• Write feet and inches separately, such as 6’2″, to avoid confusion with a decimal.
• Check your answer by converting back in the other direction.

Common mistakes

• Writing 5.6 feet when you mean 5 feet 6 inches. In decimal terms, 5.6 feet is 67.2 inches, not 66 inches.
• Mixing up the symbols, so ‘ for feet and ” for inches are swapped.
• Forgetting that 12 inches make a foot, and dividing by 10 instead, as if the system were metric.
• Rounding a height to the nearest foot and losing the inches, which can matter for clothing, furniture and doorways.

Frequently asked questions

How many inches are in a foot?

Exactly 12 inches. This is a definition, not a measurement that changes.

How many inches are in 3 feet?

36 inches, because 3 x 12 = 36.

How do I convert 5 feet 6 inches to inches?

Multiply 5 x 12 = 60, then add 6, giving 66 inches in total.

How many feet are in 72 inches?

6 feet, because 72 / 12 = 6.

Is a foot the same in every country?

The international foot used today is the same everywhere: exactly 0.3048 metres, or 30.48 centimetres. Older local feet varied, but they are no longer used for everyday measurement.