Volume Conversions

Convert volume and capacity units — liters, gallons, cups, milliliters, and more. Free calculators for cooking, chemistry, and fuel measurement.

7 units · 7 calculators

Volume measures three-dimensional space — how much liquid a container holds or how much space a solid occupies. Metric uses liters and milliliters; US customary uses gallons, quarts, cups, and fluid ounces.

US gallons and imperial (UK) gallons differ: one US gallon is about 3.785 liters while one imperial gallon is about 4.546 liters. Our converters label units clearly so you apply the right factor for your region.

Fuel economy, beverage packaging, and chemical dilution all depend on consistent volume units. When a label says gallons without specifying US or imperial, check the country of sale before converting to liters.

Quick volume calculator

Volume Calculator

Formulas & rules

  • US gallons × 3.78541 = liters
  • liters × 1000 = milliliters
  • US fluid ounces × 29.5735 = milliliters
  • US cups × 236.588 = milliliters

Popular volume conversions

Real-world example

A European recipe lists 500 ml of stock but you only have a measuring cup marked in US cups. Converting 500 ml gives about 2.1 cups — enough to scale the recipe accurately.

Common mistakes

  • Treating UK imperial gallons like US gallons at the gas pump.
  • Confusing dry cups with liquid cups in baking (use weight for precision).
  • Rounding ml to cups twice when scaling a recipe — round once at the final step.

All volume conversions

Volume units explained

Milliliters (ml)
Also: milliliters, mL
Liters (L) · base unit
Also: liters, l
Gallons (US) (gal)
Also: gallons
Quarts (US) (qt)
Also: quarts
Pints (US) (pt)
Also: pints
Cups (US) (cup)
Also: cups
Fluid Ounces (US) (fl oz)
Also: fluid ounces, fl. oz.

Frequently asked questions

How many milliliters are in a cup?
One US customary cup equals 236.588 ml. Metric cups (250 ml) are used in some countries — check which standard your recipe uses.
Is a US gallon the same as a UK gallon?
No. A US gallon is smaller (≈ 3.785 L) than an imperial gallon (≈ 4.546 L). Always confirm which gallon type you need.

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