Converting Height Between Feet/Inches and Centimeters Accurately
Converting a height like 5 feet 8 inches to centimeters requires first converting the whole height to a single unit (total inches: 5 × 12 + 8 = 68 inches), then applying the inch-to-centimeter conversion factor (68 × 2.54 = 172.72 cm) — converting the feet and inches portions separately and then trying to combine the results afterward is a common source of error.
Height is a common source of conversion confusion specifically because it's usually expressed as a combined feet-and-inches figure rather than a single unit.
A worked example
5 feet 8 inches to centimeters: convert to total inches first (5 feet × 12 inches/foot = 60 inches, plus 8 inches = 68 total inches), then multiply by the exact conversion factor (68 × 2.54 = 172.72 cm) — a two-step process that avoids trying to convert feet and inches independently and combine them afterward.
The reverse direction: centimeters to feet and inches
175 cm to feet and inches: first convert to total inches (175 ÷ 2.54 ≈ 68.9 inches), then divide by 12 to find whole feet (68.9 ÷ 12 ≈ 5 feet, with a remainder), and the remaining inches (68.9 − 60 = 8.9, rounding to about 9 inches) gives approximately 5 feet 9 inches.
Why converting to a single intermediate unit first matters
Attempting to convert the "feet" portion and "inches" portion of a height separately and then combine the two converted results tends to introduce errors, since the two portions don't convert to independent, addable centimeter values in a straightforward way — converting the whole height to one unit (total inches) first, then converting that single value, is the reliable method.