Feet and Inches to CM Converter — Instant Height Conversion with Visual Comparison

How to use the feet and inches to cm converter

This converter works in both directions. Pick Feet + Inches → CM to convert an imperial height to metric, or CM → Feet + Inches to go the other way. In the imperial panel, type the feet value and the inches value into two separate fields. The result updates as you type — you never have to press a "Convert" button.

The inches field accepts decimals and fractions. Type 10.5, 10 1/2, or 3/8 and the tool parses each of them into the correct decimal value before running the conversion. That means a measurement like 6 ft 3 1/2 in can be entered directly — no manual fraction-to-decimal step. If you only know inches (for example a pipe diameter of 18 inches), leave the feet field at 0 and enter the inches value alone.

Below the main result you will find secondary values: meters, total inches, and the same height expressed in decimal feet (so 5'10" also shows as 5.833 ft). Underneath those cards is a live visual height comparison chart that plots your value against two reference bars representing approximate average adult heights. Below the tool is a searchable reference table listing every whole-inch height from 4'0" to 7'0" with its centimeter, meter, and total-inch equivalents.

The conversion formula (and why it is exact)

The conversion relies on one of the few exact definitions in the imperial system. Since the 1959 International Yard and Pound Agreement, one inch is defined as exactly 2.54 centimeters, and one foot is exactly 30.48 centimeters. These are legal definitions in the United States, United Kingdom, Canada, Australia, New Zealand, and South Africa — not approximations.

Worked example — 5 feet 10 inches. First convert feet to inches: 5 × 12 = 60 inches. Add the extra inches: 60 + 10 = 70 total inches. Multiply by 2.54: 70 × 2.54 = 177.8 cm.

Worked example — 5 feet 5 inches. 5 × 12 = 60, 60 + 5 = 65 total inches. 65 × 2.54 = 165.1 cm.

Reverse direction (cm → feet and inches). Divide the centimeter value by 2.54 to get total inches, then divide by 12 — the whole-number part is the feet, and the remainder (multiplied by 12) is the inches. Example: 170 cm. 170 ÷ 2.54 = 66.93 total inches. 66.93 ÷ 12 = 5 feet with 6.93 inches remaining, so 170 cm ≈ 5'7". The reverse conversion is what tools like medical forms and clothing size charts require when only centimeters are given.

Why the conversion is exact (a short history)

Before 1959, the exact length of an inch varied slightly between countries. The United States used its own "US survey foot" (defined in terms of the meter but with a slightly different value), while the British imperial inch was defined in terms of a physical prototype. International trade, science, and engineering needed a single common definition, so in 1959 the major English-speaking countries signed the International Yard and Pound Agreement. The agreement fixed the inch at exactly 2.54 centimeters and, consequently, the foot at exactly 30.48 centimeters. Every modern calculator — including this one — uses those exact values. There is no rounding error in the conversion itself; the only place a value is rounded is at the display stage.

Common heights in centimeters

The table below lists frequently searched height conversions. Every value on this page uses the exact 1 inch = 2.54 cm ratio.

Why people need this conversion

The feet-and-inches system remains the standard for everyday height in the United States, the United Kingdom, Ireland, and a handful of other countries, while most of the world reports height in centimeters. That mismatch creates a steady demand for accurate conversion in many real-world situations:

• Medical and health records. International medical forms — including many from national health services — record height in centimeters. Converting your known height avoids guesswork, and accurate height matters for BMI, medication dosing, and paediatric growth charts.
• Immigration and visa paperwork. Applications for visas, residence permits, and some passport renewals in metric countries ask for height in centimeters.
• Online shopping. Clothing size charts from European and Asian retailers frequently list body-height ranges in centimeters. Knowing your height in cm makes size selection faster, especially for tailored items like suits and bridal wear.
• Sports and fitness. Competition categories in many sports, racket and bicycle sizing guides, and many fitness apps use centimeters. Sports like rowing, basketball, and combat sports have explicit height tiers.
• Construction, woodworking, and DIY. Architectural drawings and imported product specifications use millimeters and centimeters. Converting a 6-foot ceiling height, a 3-foot door opening, or a 2-inch pipe diameter requires the exact 2.54 ratio, not a rounded one.
• Science and engineering. The metric system is the international standard in scientific publishing, so any measurement reported in feet and inches must be converted before comparison or publication.
• International travel. Some airline seat reservation forms, ski rental forms, and theme-park ride restrictions ask for height in centimeters.

Working with fractional inches

Fractional inches are the norm in construction, woodworking, plumbing, and crafts. Rather than forcing you to mentally convert 3/8 into 0.375 before typing, this tool accepts the fraction directly. Enter 3/8, 10 1/2, or any other fraction in the inches field and the converter parses it correctly. Mixed numbers like 6 3/4 work too. This is the same convention you'll find on a tape measure, so you can read a measurement off the tape and type it straight into the tool without an intermediate step.

How accurate is the result?

The underlying mathematics is exact, because the imperial-to-metric definitions are exact. The only source of any approximation is the display precision. By default this converter shows two decimal places for centimeters, which is more than sufficient for height, clothing, and even most construction tasks. If you need the full-precision value, the Copy result and Copy summary buttons capture the unrounded number.

The visual comparison chart uses approximate adult reference heights. It is designed as a quick visual aid, not a statistical statement about individuals. Two different people at the same height can have very different body proportions and still register the same number.

Common mistakes when converting heights

• Forgetting to add the inches. Someone entering 5'10" sometimes converts 5 feet alone to 152.4 cm and forgets the 10 extra inches. The correct value is 177.8 cm.
• Mixing up 5.5 feet and 5'5". These are not the same. 5.5 feet = 5 feet 6 inches = 167.64 cm. 5'5" = 5.4167 feet = 165.1 cm. The decimal foot representation and the feet-and-inches representation are different formats for the same kind of information — do not confuse them.
• Rounding too early. Converting inches to centimeters, rounding, and then adding to the feet value compounds the error. Always convert the full total-inches figure, then round once at the end.
• Assuming a "survey foot" is still in use. The US survey foot was retired from most federal use at the end of 2022. For everyday purposes, 1 foot = 30.48 cm exactly.
• Confusing centimeters and meters. A height of 178 is 178 cm, not 178 m. Meters are centimeters divided by 100, so 178 cm = 1.78 m.

Limitations

• The tool converts between feet/inches and centimeters (with meters shown as a secondary output). It does not directly accept meters as a primary input field — if you have a value in meters, multiply by 100 to get centimeters first.
• It uses the modern (post-1959) international foot. It does not implement the historical US survey foot, which differed by approximately 2 parts per million.
• The visual comparison chart uses rounded population averages and should not be used for any clinical, medical, or demographic assessment.
• Very large inputs (e.g., hundreds of feet) are accepted but the visual chart's reference bars become unreadable at extreme scales. The numeric result remains correct in all cases.

Frequently asked questions

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