What Is Height Conversion?
A nurse in Chicago measures a patient at 175 centimeters. The electronic medical record system requires height in feet and inches. She needs to convert quickly and accurately. 175 cm divided by 2.54 gives 68.9 inches, which is 5 feet 8.9 inches. A miscalculation here could affect medication dosing, which often depends on exact height and weight. Precision matters.
Height conversion translates measurements between the metric system (centimeters, meters) and the imperial system (feet, inches). The United States is one of only three countries that still uses the imperial system for everyday measurements, along with Liberia and Myanmar. Most of the world uses centimeters. Whether you are filling out a medical form, shopping for clothing from an international retailer, or calculating your BMI, you need accurate height conversion.
According to the NIST, the inch is legally defined as exactly 2.54 centimeters. This conversion factor was established by international agreement in 1959 and is codified in US law. The CDC's latest NHANES data from August 2021 to August 2023, released in June 2025, reports the average US adult male at 68.9 inches (175.0 cm) and the average female at 63.5 inches (161.3 cm).
What This Calculator Does
Enter your height in any format and this calculator converts it to all other common units instantly. It handles feet and inches, decimal feet, inches, centimeters, and meters.
- cm to ft and in: Enter a height in centimeters and get feet, inches, meters, and millimeters
- ft and in to cm: Enter feet and inches and get centimeters and meters
How the Calculation Works
All conversions flow through inches as the intermediate unit, using the legally defined conversion factor of 1 inch = 2.54 centimeters exactly.
1 inch = 2.54 cm (exact, by international agreement)
1 foot = 12 inches = 30.48 cm
1 meter = 100 cm = 39.3701 inches
To convert from centimeters to feet and inches: divide by 2.54 to get total inches, then divide by 12 to get feet, with the remainder as inches. To convert from feet and inches to centimeters: multiply feet by 12, add the inches, then multiply by 2.54. For general unit conversions beyond height, try our Unit Converter.
How to Use the Calculator
- Select the conversion direction using the toggle at the top
- Enter your height value in the input field
- The result appears instantly with all equivalent units displayed
- Switch modes at any time to convert in the opposite direction
Example Calculations
Example 1:Dr. Kim, a pediatrician in San Francisco, records a patient's height as 162 cm during a checkup. The parents ask what that is in feet and inches. She enters 162 in the centimeters field. The calculator shows 5 feet 3.8 inches, 63.8 inches, and 1.62 meters. She uses this to plot the child on a growth chart that uses inches.
Example 2: James, a college basketball player in Lexington, is listed as 6 foot 7 on his roster. He enters 6 feet 7 inches. The calculator shows 79 inches, 200.66 cm, and 2.01 meters. He needs this for an international tournament registration form that requires metric units.
Example 3: Sarah, an online shopper in Denver, finds a dress on a UK website with a height recommendation of 168 cm. She enters 168 in the centimeters field. The result is 5 feet 6.1 inches. She is 5 foot 6, so the dress should fit. For calculating BMI from her height and weight, she uses our BMI Calculator.
Real World Scenarios
Medical and Health Records
Medical systems around the world use different units. US records typically use feet and inches, while international systems use centimeters. A patient transferring from a clinic in London to one in New York needs their 178 cm height converted to 5 feet 10 inches for the US record. Medication dosing for children is often calculated by body surface area, which requires precise height in centimeters. An error of even one inch can affect the dose.
Fitness and BMI Calculation
BMI calculations require height in meters and weight in kilograms. If you know your height as 5 foot 9 and weight as 175 pounds, you need to convert height to 1.753 meters and weight to 79.4 kg before calculating BMI. This calculator handles the height conversion. For the full BMI calculation, use our BMI Calculator or Ideal Weight Calculator.
International Travel and Shopping
Airlines, amusement parks, and clothing retailers around the world use metric measurements. A roller coaster at Disneyland Paris has a height requirement of 130 cm. A parent from Atlanta whose child is 4 foot 1 needs to know that equals 124 cm, meaning the child is 6 cm too short. Clothing size charts from European and Asian retailers list heights in centimeters, requiring conversion for US shoppers.
Common Mistakes to Avoid
- Confusing decimal feet with feet and inches: 5.5 feet is not 5 feet 5 inches. It is 5 feet 6 inches. Decimal feet use base 10, while inches use base 12. To convert 0.5 feet to inches, multiply by 12 to get 6 inches. This is the most common height conversion error.
- Using approximate conversion factors: Some people use 2.5 cm per inch instead of the exact 2.54. Over 70 inches, this creates a 2.8 cm error, which is more than an inch. Always use the exact factor of 2.54 established by international agreement in 1959.
- Rounding too early: When converting 180 cm to feet and inches, first divide by 2.54 to get 70.866 inches, then divide by 12 to get 5.9055 feet. The integer part is 5 feet, and the remainder 0.9055 x 12 = 10.87 inches. Rounding 70.866 to 71 before dividing would give 5 feet 11 inches, which is wrong.
- Forgetting that 1 foot = 30.48 cm exactly: Some people approximate 1 foot as 30 cm. Over 6 feet, this creates a 2.88 cm error. Use 30.48 cm per foot for precise conversions.
Limitations of This Calculator
This calculator converts between standard height units used for human height measurement. It does not handle survey feet, which differ slightly from international feet (1 survey foot = 1200/3937 meters versus 1 international foot = 0.3048 meters exactly). The difference is about 0.0006 feet per foot, which matters only in large-scale surveying and mapping applications. The calculator rounds results to a practical precision (typically 0.1 inches or 0.01 cm). For scientific applications requiring more decimal places, use the raw conversion factors directly. For general unit conversions including length, weight, and volume, try our Conversion Calculator.
Authoritative Research and Resources
- NIST Unit Conversion Resources provides the official US government reference for measurement conversions, including the legally defined factor of 1 inch = 2.54 cm exactly, established by international agreement in 1959 and codified in US law.
- CDC FastStats: Body Measurements publishes the latest NHANES anthropometric data. As of the August 2021 to August 2023 survey released in June 2025, the average US adult male is 68.9 inches (175.0 cm) tall and the average female is 63.5 inches (161.3 cm) tall.
- NIST SP 811: Guide to the SI provides detailed conversion factors and rounding guidance for technical applications, including the distinction between the international foot and the US survey foot used in land surveying.