Feet to Inches Calculator: Convert ft to in

This calculator converts a length in feet to inches. Enter the number of feet, and you get the equivalent in inches instantly. The formula is simple: multiply the feet value by 12.

Formula

The conversion between feet and inches is one of the most straightforward in the imperial system:

inches = feet × 12

Where:

• feet is the length in feet (unit: ft)
• inches is the length in inches (unit: in)
• 12 is the exact number of inches in one foot

This is an exact definition, not an approximation. The international yard is defined as exactly 0.9144 meters, and since one yard equals 3 feet, one foot is exactly 0.3048 meters. One inch is exactly 2.54 centimeters, so 12 inches make exactly one foot.

Worked Example

Using the default value of 5 feet:

1. Start with the length in feet: 5 ft
2. Multiply by 12 (inches per foot): 5 × 12 = 60
3. The result is 60 inches

So 5 feet equals 60 inches. The calculator shows 60.00 inches with two decimal places.

When to Use This Conversion

Feet-to-inches conversion appears in many everyday situations:

• Home improvement: Measuring lumber, countertops, or wall heights. A 2×4 is actually 1.5 × 3.5 inches, but lengths are often quoted in feet.
• Furniture: A sofa listed as 6 feet long is 72 inches, which matters when checking if it fits through a door.
• Clothing and body measurements: Height is commonly given as 5’10”; converting to inches (70) is needed for some forms or medical records.
• Construction and carpentry: Blueprints often use feet and inches, but material orders may require inches.
• Sports: High jump or long jump distances are sometimes reported in feet and inches, but records may be kept in inches.

Because the conversion is exact, there is no rounding error when you multiply by 12. However, if you start with a measurement that is already an approximation (e.g., a tape measure reading), the result carries that same uncertainty.

Common Mistakes and How to Avoid Them

Even a simple conversion can go wrong. Watch out for these:

• Dividing instead of multiplying: To go from feet to inches, multiply by 12. To go the other way (inches to feet), divide by 12. Mixing these up is the most common error.
• Forgetting fractional feet: If you have 5.5 feet, the answer is 66 inches, not 5 feet 5 inches. The decimal part is in feet, not inches.
• Confusing with yards: 1 yard = 3 feet = 36 inches. Some people mistakenly use 3 or 36.
• Rounding too early: If you convert 2.54 cm to inches (1 inch) and then to feet, round only at the end to avoid compounding errors.

For example, a common mistake is to convert 5.25 feet as 5 feet 2.5 inches. But 0.25 feet is 3 inches (0.25 × 12), so the correct answer is 5 feet 3 inches. Always multiply the decimal part of the feet by 12 to get inches.

Feet and Inches in Context

The imperial system uses feet and inches for many everyday measurements in the United States, while most of the world uses the metric system. Here are some reference points:

• 1 foot = 12 inches = 0.3048 meters
• 1 inch = 2.54 centimeters exactly
• 1 meter ≈ 39.37 inches ≈ 3.281 feet
• 1 yard = 3 feet = 36 inches
• 1 mile = 5,280 feet = 63,360 inches

If you need to convert to metric, you can do it in two steps: feet to inches (multiply by 12), then inches to centimeters (multiply by 2.54). For example, 5 feet = 60 inches = 152.4 cm = 1.524 m.

Limits of This Calculator

This calculator works with decimal feet. If you have a measurement in feet and inches (like 5′ 10″), you need to convert the inches part to a decimal of a foot first: divide the inches by 12 and add to the feet. For 5′ 10″, that is 5 + 10/12 = 5.8333 feet. Then multiply by 12 to get 70 inches.

The calculator is exact for any non-negative number of feet. It does not handle negative values (which would be meaningless for length) and it does not convert to other units like centimeters or meters directly—but you can do that with a separate calculator.

Frequently Asked Questions

How many inches are in a foot?

There are exactly 12 inches in one foot. This is a fixed definition in both the US customary and imperial systems.

How do I convert feet and inches to just inches?

Multiply the feet part by 12 and add the inches part. For example, 6′ 2″ = 6 × 12 + 2 = 74 inches.

How do I convert inches to feet?

Divide the number of inches by 12. The quotient is the number of feet, and the remainder is the leftover inches. For 74 inches: 74 ÷ 12 = 6 feet with a remainder of 2 inches, so 6′ 2″.

Is a foot exactly 12 inches?

Yes, the relationship is exact by definition. One foot is exactly 12 inches, and one inch is exactly 2.54 centimeters.

Why are there 12 inches in a foot?

The number 12 has historical roots; it is easily divisible by 2, 3, 4, and 6, which made fractions convenient in carpentry and trade. The foot as a unit dates back to ancient civilizations, but the 12-inch foot became standard in English-speaking countries.

How do I convert 5 feet 8 inches to centimeters?

First convert to inches: 5 × 12 + 8 = 68 inches. Then multiply by 2.54: 68 × 2.54 = 172.72 cm. So 5′ 8″ is 172.72 cm.

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in ft | Feet | ft | 5 | 0
out in | Inches | in | ft * 12 | 2