Short answer: Multiply fluid ounces by the correct conversion factor: for US fluid ounces use 0.0295735295625, for Imperial (UK) fluid ounces use 0.0284130625. If you have an ounce of mass (weight) you must know the substance’s density.
Explanation
1) US fluid ounces → liters
- Formula: $$L=\text{fl oz}_{US}\times 0.0295735295625$$
- Example: a 12‑fl‑oz can of soda: $$L=12\times0.0295735295625=0.35488235475\approx0.355\ \text{L}$$
2) Imperial (UK) fluid ounces → liters
- Formula: $$L=\text{fl oz}_{Imp}\times0.0284130625$$
- Example: an Imperial pint is 20 fl oz: $$L=20\times0.0284130625=0.56826125\ \text{L}$$
3) Ounces (mass) → liters (requires density)
- If you have mass in ounces (oz) and density $\rho$ in $\text{g/mL}$, first convert mass to grams (1 oz = 28.349523125 g), then get volume:
$$V(\text{L})=\frac{\text{mass(oz)}\times28.349523125}{\rho(\text{g/mL})\times1000}$$
Or simplified: $$V(\text{L})=\frac{\text{mass(oz)}\times0.028349523125}{\rho(\text{g/mL})}$$
- Example: 8 oz (mass) of water ($\rho\approx1\ \text{g/mL}$): $$V=8\times0.028349523125/1=0.226796185\ \text{L}\approx0.227\ \text{L}$$
Quick reference
- 1 US fl oz = 29.5735295625 mL = 0.0295735295625 L
- 1 Imperial fl oz = 28.4130625 mL = 0.0284130625 L
- 1 oz (mass) = 28.349523125 g (convert to volume only if you know density)
Tips
- Always confirm whether “ounce” means fluid ounce or ounce (weight).
- For many everyday recipes, US fluid ounce is intended; in scientific work check units precisely.
- Round your final answer to the number of significant figures needed.