Inch Calculator for U.S. Measurements
An inch calculator converts between centimeters, inches, and feet-and-inches notation. In the United States, inches are still used in many everyday situations: height, TV and monitor sizes, furniture dimensions, clothing measurements, tools, lumber, hardware, and home improvement projects.
This calculator is designed for both international users who need to understand U.S. measurements and U.S. users who need to convert product dimensions from centimeters to inches.
Inch to cm and cm to inch formulas
The conversion is simple because the inch is fixed exactly in metric units.
- Inches to centimeters: inches × 2.54
- Centimeters to inches: centimeters ÷ 2.54
- Feet to inches: feet × 12
- Feet and inches to centimeters: (feet × 12 + inches) × 2.54
Common U.S. inch conversions
Why feet and inches matter in the United States
U.S. height is usually written in feet and inches. For example,
5'10"means 5 feet and 10 inches. To convert it, multiply the feet by 12 and add the remaining inches: 5 × 12 + 10 = 70 inches. Then multiply by 2.54 to get 177.8 cm.Product dimensions are different. A desk, suitcase, shelf, or package may be listed as length × width × height in inches, while an international marketplace may list the same item in centimeters. In those cases, converting each side separately is usually more useful than converting only one total length.
TV and monitor inches are diagonal sizes
A common mistake is assuming that a 55-inch TV is 55 inches wide. Screen size is measured diagonally from one corner of the display to the opposite corner. The actual width and height depend on the aspect ratio, such as 16:9 for many TVs and monitors.
Decimal inches vs. fractional inches
Decimal inches such as
10.25 in are convenient for calculators, product databases, and engineering-style specifications. Fractional inches such as 10 1/4" are easier to read on a tape measure. That is why this calculator also shows a nearest 1/16-inch value for practical measuring.When to round inch conversions
For shopping, home measurements, and general comparison, rounding to two decimal places is usually enough. For manufacturing, printing, machining, or construction, use the required tolerance for the project. Small rounding differences can matter when multiple parts need to fit together.
Frequently asked questions
How many centimeters are in 1 inch?
1 inch is exactly 2.54 centimeters.
How do I convert 170 cm to feet and inches?
170 cm ÷ 2.54 = about 66.93 inches. Since 60 inches is 5 feet, 170 cm is about 5 ft 6.93 in.
How do I convert 6 feet to centimeters?
6 feet = 72 inches. 72 × 2.54 = 182.88 cm.
Is inch written as in or with quotation marks?
Both are common. For example, 12 inches can be written as
12 in or 12". Feet are often written with an apostrophe, as in 5'10".Why does the U.S. still use inches?
The United States commonly uses U.S. customary units in daily life, construction, retail, clothing, and consumer product specs. Metric units are also used in science, medicine, international trade, and many technical fields, so conversion between inches and centimeters remains useful.
