No. 5.8 feet means 5 feet 9.6 inches, not 5 feet 8 inches. It equals 176.784 cm. A height of 5 feet 8 inches equals 172.72 cm. The difference is 4.064 cm, or 1.6 inches.
This mix-up happens when a decimal point is used as a separator between feet and inches. A decimal describes a fraction of a foot; it does not switch the remaining digits into inches. The converter above starts at the equivalent of 5.8 decimal feet. Try 172.72 cm to see the other height.
5.8 feet vs 5 feet 8 inches at a glance
| Written height | Meaning | Total inches | Centimetres |
|---|---|---|---|
| 5.8 ft | 5 ft + 0.8 of a foot | 69.6 | 176.784 |
| 5 ft 8 in | 5 feet plus 8 inches | 68 | 172.72 |
Why the decimal changes the answer
There are 12 inches in a foot. Multiply the decimal part by 12 to find the extra inches: 0.8 × 12 = 9.6 inches. That is why 5.8 feet becomes 5 feet 9.6 inches.
Work in the opposite direction for feet and inches: divide the inches by 12, then add the whole feet. For 5 feet 8 inches, calculate 5 + 8 ÷ 12 = 5.6666… decimal feet. Rounding this to 5.67 feet is useful for display, but retain the unrounded value for further calculations.
How to enter feet and inches correctly
- For 5 feet 8 inches, calculate 5 × 12 + 8 = 68 total inches.
- Choose inches in the converter and enter 68.
- Select Convert height. The centimetre result is 172.72 cm.
- For a genuine decimal value such as 5.8 ft, choose decimal feet and enter 5.8.
Other common decimal-feet mistakes
| Decimal feet | Actual feet and inches | Different from |
|---|---|---|
| 5.6 ft | 5 ft 7.2 in | 5 ft 6 in |
| 5.10 ft (= 5.1 ft) | 5 ft 1.2 in | 5 ft 10 in |
| 6.2 ft | 6 ft 2.4 in | 6 ft 2 in |
If a form says only “5.8” without a unit or explanation, ask which notation was intended. A calculator cannot resolve ambiguous source data. For a list of heights, keep the unit in its own column and use our bulk height converter.
Frequently asked questions
Is 5.8 feet equal to 173 cm?
No. Exact conversion gives 176.784 cm. Five feet eight inches is 172.72 cm, which rounds to 173 cm.
How do I write 5 feet 10 inches as a decimal?
Use 5 + 10 ÷ 12 = 5.8333… ft. Do not write 5.10 ft; that means 5.1 decimal feet.
Why does the screenshot show 176.78 instead of 176.784?
The tool rounds centimetres to two decimal places for display. The exact conversion is 176.784 cm; additional digits do not make a personal measurement more accurate.
Conversion reference: NIST units of length. This article uses the international foot of 0.3048 m and inch of 2.54 cm. Next, try the height difference calculator or read our converter screenshot guide.