How the Volume Converter Works
Volume tells you how much space something takes up, or how much liquid a container holds. Most countries measure it in milliliters and liters. The United States uses cups, quarts and gallons. The Volume Converter changes an amount from one unit into another, so you can follow a recipe from another country, compare fuel or water amounts, or size a tank.
What you enter
- The value: a number, which can have decimals.
- The unit you have (From): milliliters, liters, cubic meters, US gallons, US quarts or US cups.
- The unit you want (To): any of the same units.
How the conversion works
Every unit has a fixed size in liters. The converter turns your value into liters, and then turns the liters into the unit you chose:
liters = value x liters in the From unit result = liters / liters in the To unit
These are the sizes of the units:
| Unit | Size in liters |
|---|---|
| 1 milliliter (mL) | 0.001 |
| 1 liter (L) | 1 |
| 1 cubic meter (m³) | 1,000 |
| 1 US gallon (gal) | 3.785411784 |
| 1 US quart (qt) | 0.946352946 |
| 1 US cup | 0.2365882365 |
A US gallon is exactly 4 quarts, and a quart is exactly 4 cups. So a US gallon is 16 cups. A liter is 1,000 milliliters, and a cubic meter is 1,000 liters.
A worked example
You want to change 5 US gallons into liters.
| Step | Value |
|---|---|
| Gallons to liters (5 x 3.785411784) | 18.927 L |
The same 5 US gallons in other units:
| Unit | Amount |
|---|---|
| Milliliters | 18,927.06 mL |
| Liters | 18.927 L |
| Cubic meters | 0.018927 m³ |
| US quarts | 20 qt |
| US cups | 80 cups |
US gallons to liters
| US gallons | Liters |
|---|---|
| 1 | 3.79 |
| 2 | 7.57 |
| 5 | 18.93 |
| 10 | 37.85 |
| 20 | 75.71 |
| 50 | 189.27 |
Chart: cups in each US unit
Each bar shows how many cups fit in the unit. A quart is 4 cups, and a gallon is 16 cups.
1 cup ██ 1 cup 1 quart ████████ 4 cups 1 gallon ████████████████████████████████ 16 cups
Chart: how many liters in each unit
The green bar is the liter. The other bars are the units from the table.
1 cup ██ 0.24 L 1 quart █████████ 0.95 L 1 liter ██████████ 1 L 1 gallon ██████████████████████████████████████ 3.79 L
A quart is a little less than a liter, and a gallon is a little less than four liters.
Doing it by hand
- Liters to US gallons: divide by 3.785, or multiply by 0.2642. So 20 L is 5.28 gal.
- US gallons to liters: multiply by 3.785. So 10 gal is 37.85 L.
- Liters to quarts: multiply by 1.0567. So 2 L is 2.11 qt.
- Cups to milliliters: multiply by 236.6. So 2 cups is 473 mL.
- Cubic meters to liters: multiply by 1,000. So 0.5 m³ is 500 L.
A quick estimate: a liter is about a quart, and a gallon is about 3.8 liters. For 12 gallons, 12 x 3.8 is about 45.6 liters. The exact answer is 45.42 liters.
A bigger example: a pool
A pool is 10 m long, 5 m wide and 1.5 m deep. Its volume is 10 x 5 x 1.5 = 75 cubic meters. That is 75,000 liters, or about 19,813 US gallons.
Where these conversions are used
- Cooking: recipes may give cups or milliliters. 1 cup is about 237 mL.
- Fuel and cars: fuel is sold by the liter in most countries and by the gallon in the United States.
- Water tanks, pools and aquariums: the size is often given in cubic meters or gallons.
- Shopping: drinks and cleaning products are sold in liters, milliliters, quarts or gallons.
- Science and school: small amounts in milliliters, and large amounts in cubic meters.
Tips
- Check which gallon you mean. A US gallon is 3.785 liters, but a UK (imperial) gallon is 4.546 liters, about 20% bigger. The UK gallon is not included here.
- A US cup is not a metric cup. A US cup is 236.6 mL, and a metric cup used in some countries is 250 mL.
- Do not confuse volume and weight. A liter of water weighs about a kilogram, but a liter of oil or flour weighs a different amount. To change weight, use a weight converter.
- Fluid ounces and spoons. Fluid ounces, tablespoons and teaspoons are not in this converter. A US cup is 8 fluid ounces.
What this converter does not include
- UK (imperial) gallons, pints and fluid ounces.
- Spoon measures, such as tablespoons and teaspoons.
- Weight, length and other kinds of units.
This tool gives an estimate for general information only. For medicine, science or trade that needs a legal measure, use a calibrated measuring instrument and follow the official rules.