Volume Conversion

Convert between metric (liters, milliliters, cubic meters) and US customary units (gallons, quarts, pints, cups, fluid ounces) plus UK gallons.

Volume Conversion Formulas

Metric System Conversions

1 m³ = 1,000 L = 1,000,000 mL = 1,000,000 cm³

1 L = 1,000 mL = 1,000 cm³ = 0.001 m³

1 mL = 1 cm³

Metric system based on powers of 10

US Customary System Conversions

1 US gallon = 4 quarts = 8 pints = 16 cups = 128 fl oz

1 quart = 2 pints = 4 cups = 32 fl oz

1 pint = 2 cups = 16 fl oz

1 cup = 8 fl oz

US customary volume relationships

Imperial vs US Gallons

1 UK gallon = 4.54609 L = 1.201 US gallons

1 US gallon = 3.785411784 L = 0.8327 UK gallons

1 US gallon = 231 cubic inches

Different gallon definitions: US vs UK Imperial

Key Metric ↔ US Conversions

1 L = 0.2642 US gallons = 1.057 quarts = 2.113 pints

1 L = 4.227 cups = 33.814 fl oz

1 US gallon = 3.785411784 L (exact)

1 quart = 0.946352946 L (exact)

1 pint = 0.473176473 L (exact)

1 cup = 0.236588237 L (exact)

1 fl oz = 0.0295735296 L (exact)

International standard conversion factors

Other Key Conversions

1 UK gallon = 4.54609 L (exact)

1 L = 0.2200 UK gallons

1 cubic inch = 16.387 cm³

1 m³ = 1,000 L = 264.2 US gallons

Additional conversion factors

Reference Volume Values

Reference Volume Liters (L) US Gallons UK Gallons Cubic Meters (m³)
Teaspoon 0.005 0.0013 0.0011 0.000005
Coffee Cup 0.24 0.063 0.053 0.00024
Wine Bottle 0.75 0.198 0.165 0.00075
2-Liter Soda Bottle 2 0.528 0.440 0.002
Car Gas Tank 50 13.2 11.0 0.05
Bathtub 300 79.3 66.0 0.3
Swimming Pool (Small) 75,000 19,813 16,498 75
Olympic Pool 2,500,000 660,430 549,917 2,500
Oil Tanker Ship 318,000,000 84,000,000 70,000,000 318,000

Volume Unit Definitions

Liter (L) - Metric Standard

Primary metric unit for measuring liquid volume, equal to one cubic decimeter.

Definition: Exactly 1 cubic decimeter (1 dm³) or 0.001 cubic meters

History: Originally defined as volume of 1 kg of water at maximum density

Usage: Beverages, fuel, chemicals, medical dosages worldwide

Subdivisions: Milliliter (mL), centiliter (cL), deciliter (dL)

Milliliter (mL) - Small Volume Unit

One thousandth of a liter, equivalent to one cubic centimeter (cm³).

Definition: Exactly 0.001 liters or 1 cm³

Usage: Medicine dosages, laboratory measurements, cooking

Precision: Ideal for small, precise measurements

Medical Standard: Universal unit for liquid medications

US Gallon (gal) - American Standard

Primary large volume unit in the United States, smaller than the Imperial gallon.

Definition: Exactly 231 cubic inches = 3.785411784 liters

History: Based on the wine gallon, standardized in 1893

Usage: Fuel, beverages, paint, chemicals in US

Subdivisions: Quarts (4), pints (8), cups (16), fluid ounces (128)

US Quart (qt) - Quarter Gallon

One quarter of a US gallon, commonly used for beverages and cooking.

Definition: Exactly 1/4 US gallon = 0.946352946 liters

Usage: Milk, juice, cooking measurements, oil containers

Subdivisions: 2 pints, 4 cups, 32 fluid ounces

Practical Use: Common container size for liquids in US stores

US Pint (pt) - Half Quart

Half of a US quart, widely used in food service and retail.

Definition: Exactly 1/8 US gallon = 0.473176473 liters

Usage: Beer, ice cream, berries, cream containers

Subdivisions: 2 cups, 16 fluid ounces

Common Items: Pint glass (beer), pint of ice cream

US Cup (cup) - Cooking Standard

Standard cooking measurement in American recipes, half of a pint.

Definition: Exactly 1/16 US gallon = 0.236588237 liters (≈236.6 mL)

Usage: Cooking, baking, recipe measurements

Subdivisions: 8 fluid ounces, 16 tablespoons

Kitchen Standard: Most common recipe volume measurement in US

US Fluid Ounce (fl oz) - Small Volume Unit

Smallest common US liquid volume unit, one eighth of a cup.

Definition: Exactly 1/128 US gallon = 0.0295735296 liters (≈29.6 mL)

Usage: Beverage sizes, medication, perfume, small containers

Note: Different from weight ounce (oz) - fluid ounce measures volume

Practical Use: Shot glasses (1.5 fl oz), medicine doses, energy drinks

UK Imperial Gallon (gal) - British Standard

Larger than the US gallon, used in UK and Commonwealth countries.

Definition: Exactly 4.54609 liters, based on volume of 10 pounds of water

History: Defined in 1824 as volume of 10 pounds of water at 62°F

Usage: UK, Canada, and other Commonwealth countries

Difference: 20% larger than US gallon

Cubic Meter (m³) - Large Volume Standard

SI unit for large volumes, equal to 1,000 liters.

Definition: Volume of a cube with 1-meter sides

Usage: Construction materials, water consumption, gas storage

Practical Scale: Room volumes, swimming pools, reservoirs

Industrial Use: Concrete, natural gas, water treatment

Cubic Centimeter (cm³) - Laboratory Standard

Small precision unit, exactly equal to one milliliter.

Definition: Volume of a cube with 1-centimeter sides

Usage: Engine displacement, medical syringes, laboratory work

Equivalence: 1 cm³ = 1 mL exactly

Precision: Ideal for small, accurate measurements

Scientific Applications

Chemistry & Laboratory Science

Molarity: M = n/V (moles per liter)

Solution Preparation: Dilution calculations V₁C₁ = V₂C₂

Gas Laws: Volume-pressure-temperature relationships

Medicine & Pharmacology

Dosage Calculations: mg/mL concentrations

IV Fluid Management: Flow rates and total volumes

Blood Volume: Adult human ≈ 5-6 liters total blood volume

Engineering & Manufacturing

Fluid Dynamics: Flow rate calculations and pipe sizing

Storage Design: Tank capacity and material requirements

Process Control: Batch volumes and mixing ratios

Environmental Science

Water Treatment: Flow rates and chemical dosing

Air Quality: Pollutant concentrations (μg/m³)

Rainfall Measurement: mm of rain = L/m² of area

Food & Beverage Industry

Recipe Scaling: Proportional volume adjustments

Packaging: Container volume specifications

Quality Control: Density and consistency testing

Automotive & Aerospace

Engine Displacement: Total cylinder volume in cm³ or L

Fuel Efficiency: L/100km or miles per gallon

Fluid Capacities: Oil, coolant, hydraulic fluid volumes

Measurement Considerations

Temperature Effects

Thermal Expansion: Liquids expand with temperature increase

Standard Conditions: Volume measurements often specified at 20°C

Calibration: Measuring devices calibrated at specific temperatures

Precision and Accuracy

Meniscus Reading: Read liquid level at eye level for accuracy

Container Shape: Wide vs narrow containers affect measurement precision

Surface Tension: Can affect readings in small containers

Unit Selection Guidelines

Laboratory Work: Use mL for precise small volumes, L for larger

Engineering: m³ for large volumes, L for moderate volumes

Cooking: Follow recipe units, convert as needed

International Trade: Specify gallon type (US vs Imperial)

Fundamental Volume Equations

Basic Volume Formulas

Cube: V = a³

Cylinder: V = πr²h

Sphere: V = (4/3)πr³

Where: a = side length, r = radius, h = height

Fluid Flow Rate

Q = V/t = A·v

Where: Q = flow rate, V = volume, t = time, A = cross-sectional area, v = velocity

Density Relationship

ρ = m/V

Where: ρ = density, m = mass, V = volume

Ideal Gas Law (Volume)

V = nRT/P

Where: V = volume, n = moles, R = gas constant, T = temperature, P = pressure