Why 5.8 feet is not 5 feet 8 inches
A decimal value of 5.8 feet contains 5 whole feet and 0.8 of another foot. Multiply that fraction by 12 to get 9.6 inches. In contrast, 5 feet 8 inches contains 8/12 of a foot, or approximately 5.6666667 decimal feet.
This matters when copying a height into a form or comparing furniture dimensions. First check whether the form has a single decimal-feet field, separate feet and inches fields, or a centimeter field. Avoid interpreting the punctuation in an unfamiliar listing as a decimal number.
Turn 170 cm into both readings
- Open the Length Converter with centimeters to feet selected.
- Enter 170. The main result is approximately 5.57742782152 ft.
- Read the companion line: 5 ft 6.93 in, with inches rounded to two decimals.
- If the destination requires whole inches, round the complete height to 5 ft 7 in. If it accepts centimeters, keep 170 cm instead of introducing extra rounding.
You can reproduce the arithmetic: 170 ÷ 30.48 ≈ 5.57742782152. The remaining inches are (5.57742782152 − 5) × 12 ≈ 6.929133858. The long decimal is calculation precision, not a claim that the original measurement was that precise.
Enter feet and inches as total inches
The converter takes one number, so for 5 feet 8 inches choose Inch as From and Centimeter as To. Enter 68, because (5 × 12) + 8 = 68. The result is 172.72 cm. This avoids typing a repeating decimal-foot value.
| Reading | Total inches | Centimeters |
|---|---|---|
| 5 ft 8 in | 68 | 172.72 |
| 5.8 decimal ft | 69.6 | 176.784 |
| 170 cm | ≈ 66.9291 | 170 |
Entering 5.8 when you mean 5 ft 8 in adds 4.064 cm. The unit conversion is correct for the entered value; the mistake is the interpretation of that value.
Round once, for the destination
Use the full source measurement and round after converting. If a form asks for two decimal places in feet, 170 cm becomes 5.58 ft. If it asks for feet and whole inches, use 5 and 7. Those are different display conventions, so a small difference when converting the rounded answers back is expected.
The converter uses international inches and feet: 1 inch is exactly 2.54 cm and 1 foot is exactly 30.48 cm. It does not use historical survey feet. For a length taken with a ruler or tape, measurement uncertainty remains after conversion. A conversion does not make a loosely measured height more accurate.
References and corrections
These examples describe the stated inputs and checks. They do not establish compatibility with every browser, encoder, or receiving service. Found a different result? Send a reproducible example.