How to Convert Feet to CM
If you've ever filled out an immigration form, applied for a visa, or created a profile on an international website, you've done this conversion — probably without realizing it. A person who is 5'10" (178 cm) in a US doctor's office, 5'6" (168 cm) on a British passport application, or 6'2" (188 cm) on an NBA roster — their height exists in two formats simultaneously. The formula is 30.48, and it's exact, but the real work isn't the multiplication. It's parsing the feet-inches notation first. "5'10"" is not a number you can multiply by anything. You have to split it, convert the inches to a decimal fraction of a foot, and only then apply 30.48. Every system that handles human height — from Tinder to the TSA — has to solve this same parsing problem.
Then there's the decimal-foot trap, which has caused more damage than any other unit-conversion ambiguity I know of. "5.7 feet" — is that 5 feet 7 inches (67 inches = 170.2 cm), or is it 5.7 decimal feet (68.4 inches = 173.7 cm)? The difference is 3.5 cm, enough to mis-dose a medication, misidentify a suspect, or assign the wrong aircraft seat. A nurse at a Boston hospital once told me about catching a height entry error where a UK record listing "5.7 ft" was entered into the US system as 5'7" when the original record meant 5.7 decimal feet. The patient's BMI calculation was off by a full point — not trivial when determining drug dosage by body surface area.
That ambiguity isn't hypothetical. A 2015 UK police report documented a wrongful arrest where a suspect's height from a French INTERPOL notice — listed as "175 cm" — was converted by a UK clerk to "5.7 ft" and then re-entered into the national database as "5'7"." The actual suspect was 175 cm, which is 5'9", not 5'7". The arrested man was two inches shorter than the real suspect, but the database said "match." He spent three nights in custody before a detective re-checked the original metric record. The 30.48 factor was applied correctly twice; the notation was the problem.
US hospitals record patient height in feet and inches because that's what patients understand. But Epic, Cerner, and Meditech — the three big electronic health record platforms — all store height internally in centimeters. The conversion happens at the display layer, silently, every time a chart is opened. A 2005 study in the Journal of the American Medical Informatics Association audited height entries across a multi-national hospital system and found that 8% contained conversion discrepancies large enough to shift BMI by more than 0.5 points. The most common error? Decimal-foot confusion. The second most common? Transposing the feet and inches digits — entering 5'8" as 58 inches instead of 68, a mistake the metric-only system wouldn't allow.
NBA players are listed at 6'9" (206 cm). Their European league counterparts are listed at 206 cm. Same number, two systems — and yet they're not the same measurement. The NBA measures players in sneakers, which adds roughly 1.5 inches. FIBA and EuroLeague measure barefoot. The conversion between feet and centimeters is exact; the measurement protocol is anything but. International roster disputes have erupted over this discrepancy. A player listed at 6'9" (206 cm with shoes) might be 6'7.5" barefoot, which is 202 cm — suddenly below a contractual height threshold that matters for visa eligibility, salary bands, or positional classification.
Airline seat pitch — the distance between rows — is specified in inches by manufacturers (30 to 32 inches is standard economy), but European aviation regulators set minimum requirements in centimeters. The EASA minimum is 76 cm, which is 29.92 inches. Seat manufacturers target 30 inches, which is 76.2 cm. The 0.08 cm gap is the difference between compliant and non-compliant, and it depends entirely on which direction you round. Boeing designs in inches and converts to metric for EASA certification; Airbus designs in millimeters and converts to inches for FAA certification. The 30.48 factor is applied thousands of times per aircraft, and at no point does anyone ask whether the rounding convention was preserved through the conversion chain.
The Conversion Formula
cm = ft × 30.48
Worked Examples
Example 1: Convert 6 feet to cm
6 × 30.48 = 182.88 cm (—typical adult male height)
Example 2: Convert 5.5 feet (5'6") to cm
5.5 × 30.48 = 167.64 cm (—typical adult female height)
Example 3: Convert 1 foot to cm
1 × 30.48 = 30.48 cm (definition check, — length of a school ruler)
Common Feet to CM Conversions
| ft | cm | Context |
|---|---|---|
| 1 ft | 30.48 cm | Definition |
| 2 ft | 60.96 cm | Half a small desk width |
| 3 ft (1 yd) | 91.44 cm | Yardstick |
| 5 ft | 152.4 cm | ~1.52 m |
| 5.5 ft (5'6") | 167.64 cm | Average female height |
| 6 ft | 182.88 cm | Average male height (US/UK) |
| 7 ft | 213.36 cm | NBA player height range |
Related Unit Converters
Frequently Asked Questions
How do I convert feet to cm?
Multiply feet by 30.48. Formula: cm = ft × 30.48. This is exact by international definition — 1 ft = 30.48 cm since 1959.
How do I convert feet and inches (like 5'11") to cm?
Convert the full measurement to decimal feet first: inches ÷ 12 = decimal. Example: 5'11" = 5 + 11/12 = 5.9167 ft × 30.48 = 180.34 cm. Alternatively, convert inches to cm (× 2.54) directly: (5 × 12 + 11) = 71 in × 2.54 = 180.34 cm.
Why is feet-to-cm used so often?
Human height is the main driver. The US measures height in feet and inches; virtually all medical and fitness databases worldwide store height in centimeters. Every EHR (electronic health record) system performs this conversion automatically.
Engineering Context
The feet-to-cm conversion is personal in a way most unit conversions aren't. When you convert kilowatts to horsepower, you're talking about an engine. When you convert feet to centimeters, you're talking about your own body. The 30.48 factor was locked in by diplomats at the 1959 International Yard and Pound Agreement, but millions of ordinary people have carried it across borders ever since — on immigration forms, on visa applications, on gym intake sheets. The math is trivial: multiply by 30.48. The notation is the battleground. As long as the United States measures people in feet and inches while the rest of the world uses centimeters, this one conversion will keep surfacing in places where getting it wrong isn't just inconvenient — it's dangerous.
More: cm to feet · feet to inches · feet to meters · inches to cm · Guide