Cubic Feet to Liters Volume Converter
Common Conversions
| ft³ | L |
|---|---|
| 0.1 | 2.832 |
| 0.5 | 14.158 |
| 1 | 28.317 |
| 2 | 56.634 |
| 5 | 141.584 |
| 10 | 283.168 |
| 25 | 707.921 |
| 50 | 1415.842 |
| 100 | 2831.685 |
| 1000 | 28316.847 |
Why this conversion matters in chemistry
Gas cylinders, fume hood volumes, and air-flow specs in a US-built lab are all routinely quoted in ft³ or CFM. A 200 ft³ argon cylinder holds about 5.66 m³, or 5660 L — a useful number when estimating how long a glovebox purge will last, or how many hours of inert-atmosphere chemistry the cylinder can support before a refill. The factor is 28.3168 L per ft³, which comes straight out of (30.48 cm)³, since 1 ft is exactly 30.48 cm. The arithmetic is a utility rather than anything chemical, but it's the conversion that lets a US catalog spec meet a metric safety calculation.
Formula
Where the factor comes from
This pair joins two definitions from separate systems, and since both are exact, so is their product. On the imperial side the inch is fixed at exactly 25.4 mm by international agreement, which makes a foot exactly 30.48 cm. On the metric side the liter is fixed at exactly one cubic decimeter, or 1000 cm³. Route the calculation through centimeters and it closes without a remainder: 30.48³ = 28316.846592 cm³ in a cubic foot, which is 28.316846592 L. Both defining acts were administrative rather than experimental, so there is no uncertainty to propagate and no future revision to anticipate. Set that against a conversion like gallons of solvent to kilograms, where a measured density enters and the answer arrives carrying error bars.
Precision and significant figures
Equipment nameplates, not instruments, are where cubic-foot values usually come from, and the factor being exact means every significant figure in the answer is inherited from that nameplate. Three figures is generous for most of them. The digits do earn attention in the flow-rate form: 1 CFM is 28.316846592 L/min, or 0.4719 L/s, and that per-second figure is used often enough to be worth carrying to four places. The familiar shortcut of 28.3 L per cubic foot runs six parts in ten thousand low, which no hood balance will ever resolve. Using a flat 28 costs 1.1 percent, and that much can surface when a calculated air-change rate is compared against a metered one.
Worked Examples
One cubic foot of gas — the anchor number, exact from the definition of the foot.
A small compressed-gas cylinder capacity, useful when estimating a glovebox purge budget.
Roughly what 1 L looks like back in ft³ — a sanity check when specs are quoted in mixed units.
Common mistakes
Standard cubic feet are quantity, not space
A volume labeled standard is referenced to fixed conditions, which makes it a statement about how much gas there is rather than about how much room it occupies. Actual cubic feet describe the volume at the real temperature and pressure. Either converts to liters with the same factor, but the two cannot be compared until the gas law has brought them to common conditions.
The reverse factor is not 0.035
Going from liters back to cubic feet means dividing by 28.316846592, or multiplying by 0.035315. The tempting round 0.035 is nearly one percent low, and rounding the forward and reverse factors independently means a value that makes the round trip no longer lands where it started. Divide by the forward factor rather than storing a separately rounded reciprocal.
Shell volume against working volume
Almost every cubic-foot figure a chemist meets describes a gas or an enclosure, so the converted liters usually belong in a gas-law or ventilation calculation rather than a solution recipe. Where a tank capacity in cubic feet is being turned into liters of liquid charge, establish whether the number is total shell volume or the working volume left once freeboard and internals are subtracted.