Last updated: May 2026
Convert between liters, milliliters, gallons, fluid ounces, cups, pints, quarts, and tablespoons — metric to US and back.
Convert between liters, ml, gallons, cups, fl oz, pints, quarts, and more
Common Volume References
| Metric | US Imperial | Context |
|---|---|---|
| 5 ml | 1 tsp | Medicine dosing, baking |
| 15 ml | 1 tbsp | Cooking |
| 237 ml | 1 cup | Baking standard |
| 500 ml | 16.9 fl oz | Standard water bottle |
| 1 liter | 33.8 fl oz / 4.23 cups | Large water bottle |
| 3.785 L | 1 US gallon | Gas station fuel |
Other Unit Converters
Volume conversions cause more kitchen confusion than almost anything else. The core problem: US recipes use cups, tablespoons, and fluid ounces while the rest of the world uses milliliters and liters. These don't convert to clean round numbers. One US cup is 236.588 ml. One tablespoon is 14.787 ml. You either round aggressively or use a calculator.
There are also two different fluid ounces in active use — the US fluid ounce (29.57 ml) and the UK fluid ounce (28.41 ml). In most recipes, the difference is negligible. In large batches or baking, it adds up.
| From | To | Multiply By | Notes |
|---|---|---|---|
| Milliliters (ml) | US fluid oz | 0.033814 | 1 fl oz ≈ 30 ml (rough) |
| US fluid oz | Milliliters | 29.5735 | Common in medicine/cooking |
| US cups | Milliliters | 236.588 | ≈ 237 ml per cup |
| Tablespoons (US) | Milliliters | 14.7868 | ≈ 15 ml per tbsp |
| Teaspoons (US) | Milliliters | 4.92892 | ≈ 5 ml per tsp |
| Liters | US gallons | 0.264172 | 1 US gal = 3.785 L |
| US gallons | Liters | 3.78541 | UK gallon = 4.546 L |
How many ml is a cup?
One US cup is 236.588 ml, typically rounded to 237 ml. Note that an Australian or Canadian "metric cup" is exactly 250 ml — slightly larger. If a recipe is from Australia, their cup is about 5.6% bigger than a US cup, which matters for baking where precision counts.
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785 liters while a UK (imperial) gallon is 4.546 liters — about 20% larger. This affects fuel economy comparisons: a car getting 30 US mpg only gets about 25 UK mpg for the same trip. Always check which gallon a figure refers to when comparing international specs.
How many teaspoons are in a tablespoon?
Exactly 3 teaspoons = 1 tablespoon in US measurements. A tablespoon is approximately 15 ml; a teaspoon is approximately 5 ml. These ratios are consistent across US, UK, and metric cooking, making them one of the few volume units that don't cause international confusion.
What's the difference between fluid ounces and weight ounces?
Fluid ounces measure volume; regular ounces measure weight (mass). For water, 1 fluid ounce ≈ 1 ounce by weight because water's density is 1 g/ml. For other liquids the numbers diverge — honey is much denser, oil is lighter. Never use weight ounces and fluid ounces interchangeably unless you're measuring water.
How do I convert liters per 100km to miles per gallon?
These scales run in opposite directions — lower L/100km means better efficiency, higher mpg means better efficiency. Formula: mpg (US) = 235.215 ÷ L/100km. So 7 L/100km = about 33.6 mpg; 5 L/100km = about 47 mpg. For UK mpg use 282.5 as the numerator instead.