Cubic Feet to Cubic Meters Volume Converter
Common Conversions
| ft³ | m³ |
|---|---|
| 0.1 | 0.00283 |
| 0.5 | 0.01416 |
| 1 | 0.02832 |
| 2 | 0.05663 |
| 5 | 0.14158 |
| 10 | 0.28317 |
| 25 | 0.70792 |
| 50 | 1.41584 |
| 100 | 2.83168 |
| 1000 | 28.3168 |
Why this conversion matters in chemistry
Cubic feet creep in any time US-sourced equipment meets a safety calculation done in SI. A 200 ft³ argon cylinder works out to 5.66 m³ — worth knowing when you're sizing an inert-atmosphere glovebox that gets refilled a couple of times a year, or setting ventilation requirements in a room where a cylinder could fail. The factor is 0.0283168 m³/ft³, which drops straight out of 1 ft = 0.3048 m cubed. There's nothing chemically interesting about the arithmetic itself, but you'll reach for it more than you'd expect in any building where imperial ductwork meets metric process design.
Formula
Where the factor comes from
The foot has had no independent physical realization since 1959, when the international yard and pound agreement fixed the yard at exactly 0.9144 m. A foot is a third of that, exactly 0.3048 m, which is the same act that makes an inch exactly 25.4 mm. Cube it: 0.3048³ = 0.028316846592, and because 0.3048 terminates so does its cube, exact to all eleven significant figures with nothing measured anywhere along the way. The exactness here is a matter of agreement rather than physics. Before 1959 the American and imperial feet differed slightly, and the US survey foot — 1200/3937 m, kept for geodetic work until it was retired at the end of 2022 — is longer by two parts per million, which cubes to six parts per million in volume.
Precision and significant figures
Eleven exact digits sit in the factor and almost none of them matter, because cubic-foot figures reaching a chemistry problem are rarely measurements. A cylinder described as 200 ft³ carries a catalog size designation; a room quoted at 1200 ft³ came from three tape-measure dimensions rounded to the nearest foot. Two or three significant figures is the honest ceiling, so 200 ft³ is 5.66 m³ and writing 5.663369 m³ claims a precision the label never offered. The rounded factor 0.0283 sits within six parts in ten thousand of exact, which is invisible at that input quality; dropping to 0.028 runs about 1.1 percent low and starts to show against a metered figure.
Worked Examples
The base conversion. Handy to keep in your head as roughly 1/35, or 2.83%.
A cubic meter of gas is a little under 36 cubic feet. This is the mental anchor for everything else.
A standard size-200 compressed gas cylinder. Worth knowing when a ventilation calculation wants the worst-case release volume in SI.
Roughly the volume of a small walk-in cold room or a generously-sized fume hood enclosure.
Common mistakes
Cylinder contents are not cylinder volume
A cylinder rated at 200 ft³ describes the gas it releases on venting to atmosphere, not the space inside the steel, which is under two cubic feet. Converting the 200 gives 5.66 m³ of gas at ambient conditions, the figure a ventilation calculation wants. Reading the same 200 as the vessel's physical capacity overstates the size of the cylinder by more than a hundredfold.
Cubic feet per minute is a rate
Hood and duct specifications come in CFM, a flow, and the factor converts only the volume part of it. 1000 CFM becomes 28.32 m³/min, or 0.472 m³/s where the calculation wants SI seconds. Dropping the time base and reporting 28.32 m³ turns a continuous exhaust rate into a one-time volume, which makes any dilution estimate built on it meaningless.
Rounding the sides before cubing
Converting each dimension to meters and then multiplying is not the same arithmetic as multiplying in feet and converting once, if the intermediates get rounded. A 12 × 20 × 9 ft room is 61.16 m³; rounding the sides to 3.7, 6.1 and 2.7 m gives 60.94 m³. The gap is small here, but the habit compounds badly once more terms enter.