Volume conversion tables and formulas
The volume converter on this page lets you instantly convert values between metric, US customary, imperial, and cubic measurement systems. Below you will find the most common conversion scenarios with ready-to-use tables and formulas.
How to convert liters to gallons and back
The most common volume conversion is between liters and US gallons. The key number to remember: 1 US gallon = 3.785 liters. To convert liters to gallons, divide by 3.785. For example, a 60-liter gas tank holds about 15.85 gallons, and a 5-gallon water jug contains about 18.9 liters.
If you are working with imperial (UK) gallons, the ratio is different: 1 imperial gallon = 4.546 liters. Always check which gallon system your source is using — the 20% difference can cause significant errors in fuel calculations, recipe scaling, and industrial processes.
Water weight: 1 cubic meter = 1 metric ton
One cubic meter of pure water at 4°C weighs exactly 1000 kg (1 metric ton). This convenient 1:1 ratio between volume in m³ and mass in metric tons makes construction calculations straightforward: a 30 m³ pool holds 30 tons of water, and the structure must support that load. Similarly, 1 liter of water weighs 1 kg and 1 mL weighs 1 gram.
Quick reference conversion table
| Unit | Metric equivalent | Common use case |
|---|---|---|
| 1 US fluid ounce (fl oz) | 29.6 mL | Beverages, medicine dosing |
| 1 US cup | 237 mL | Cooking and baking recipes |
| 1 US pint | 473 mL | Beer, ice cream |
| 1 US gallon | 3.785 L | Fuel, milk, paint |
| 1 imperial gallon | 4.546 L | UK fuel (historical), beer kegs |
| 1 cubic foot (ft³) | 28.3 L (7.48 gal) | Aquariums, water heaters, HVAC |
| 1 cubic meter (m³) | 1000 L (264.2 gal) | Water meters, construction, pools |
Cooking measurements: cups, tablespoons, fluid ounces
American recipes use cups and spoons instead of metric weights. Here are the key equivalents: 1 cup = 237 mL, 1 tablespoon (tbsp) = 15 mL, 1 teaspoon (tsp) = 5 mL, 1 fluid ounce (fl oz) = 30 mL. Precision matters in baking — even a 10% error can ruin dough or batter.
Quick kitchen cheat sheet: 4 cups ≈ 1 liter (actually 946 mL). If a recipe calls for 2 cups of milk, that is about 475 mL — just under half a liter. For tablespoons: 1 cup = 16 tbsp, so half a cup = 8 tbsp.
Automotive: engine displacement and fuel economy
Engine displacement is listed in liters (2.0 L) or cubic centimeters (2000 cc) — these are the same, since 1 L = 1000 cm³. Fuel tank capacity is given in gallons (US) or liters (metric). Fuel economy uses MPG (miles per gallon) in the US or L/100 km in metric countries. To convert: L/100 km = 235.2 ÷ MPG. For example, 30 MPG ≈ 7.8 L/100 km.
Quick mental math formulas
Liters → US gallons: divide by 4, then add 5% (1 L ÷ 4 = 0.25, +5% ≈ 0.264 gal). Or simply divide by 3.8.
US gallons → liters: multiply by 3.8 for approximate result (exact: 3.785).
Fluid ounces → mL: multiply by 30 (exact: 29.6 mL).
Cups → mL: multiply by 240 (exact: 237 mL).
Cubic feet → gallons: multiply by 7.5 (exact: 7.48 gal).
Cubic meters → liters: multiply by 1000 (this one is exact).
For precise calculations, use the converter above — it provides 6-digit decimal precision and supports 35+ units across 4 measurement systems.