Gallon Calculator
Convert between gallons and multiple volume units instantly
Multi-Unit Volume Converter
What is a Gallon?
A gallon is a unit of volume measurement used primarily in the United States and some other countries for measuring liquids. The US liquid gallon equals exactly 231 cubic inches or approximately 3.785 liters, serving as a fundamental unit for fuel pricing, beverage packaging, and liquid product sales. This imperial measurement traces its origins to the British wine gallon, though modern US and UK gallons differ significantly in volume, creating potential confusion in international contexts.
Types of Gallons
US Liquid Gallon
Volume: 231 cubic inches = 3.785411784 liters
The standard gallon for liquids in the United States, used for gasoline, milk, water, and most beverage measurements.
US Dry Gallon
Volume: 268.8025 cubic inches = 4.40488377086 liters
Rarely used today, historically measured dry goods like grains. Not commonly found in modern commerce.
Imperial Gallon (UK)
Volume: 277.42 cubic inches = 4.54609 liters
Used in the United Kingdom and some Commonwealth countries. Approximately 20% larger than the US gallon.
This calculator uses US liquid gallons as the standard, the most commonly encountered gallon measurement in everyday American life. Understanding gallon relationships with other volume units enables accurate measurement conversion for cooking, fueling vehicles, purchasing beverages, and countless other practical applications where liquid volume matters.
Convert Liters to Gallons – Metric Units
Converting liters to gallons bridges the gap between metric and imperial measurement systems. Since one US gallon equals 3.785411784 liters, dividing any liter value by this conversion factor yields gallons. This conversion proves essential when traveling internationally, purchasing fuel abroad, or following recipes from countries using metric measurements.
Conversion Formula
\[ \text{Gallons} = \frac{\text{Liters}}{3.785411784} \]
Simplified: \( \text{Gallons} \approx \frac{\text{Liters}}{3.785} \)
Examples
Example 1: Convert 5 liters to gallons
\[ 5 \div 3.785 = 1.32 \text{ gallons} \]
Example 2: Convert 10 liters to gallons
\[ 10 \div 3.785 = 2.64 \text{ gallons} \]
Quick Reference
- 1 liter ≈ 0.264 gallons
- 5 liters ≈ 1.32 gallons
- 10 liters ≈ 2.64 gallons
- 20 liters ≈ 5.28 gallons
- 100 liters ≈ 26.42 gallons
Convert Cubic Feet to Gallons & Convert Cubic Inches to Gallons
Cubic Feet to Gallons
Since one cubic foot equals 7.48051948 gallons, multiplying any cubic feet measurement by this factor yields gallons. This conversion helps when calculating pool volumes, tank capacities, or any situation where volumetric space measurements need translation to liquid gallon equivalents.
\[ \text{Gallons} = \text{Cubic Feet} \times 7.48051948 \]
Simplified: \( \text{Gallons} \approx \text{Cubic Feet} \times 7.48 \)
Example: A tank measuring 10 cubic feet
\[ 10 \times 7.48 = 74.8 \text{ gallons} \]
Cubic Inches to Gallons
One US gallon equals exactly 231 cubic inches—this is the legal definition of a US gallon. Dividing cubic inches by 231 converts directly to gallons, particularly useful for engine displacement measurements, small container volumes, and precision volumetric calculations.
\[ \text{Gallons} = \frac{\text{Cubic Inches}}{231} \]
Example: An engine with 462 cubic inch displacement
\[ 462 \div 231 = 2 \text{ gallons} \]
Convert Quarts to Gallons & Convert Ounces to Gallons
Quarts to Gallons
The quart-to-gallon conversion is straightforward: 4 quarts equal 1 gallon. This simple relationship makes mental math easy and represents one of the most common cooking and automotive fluid measurement conversions Americans encounter.
\[ \text{Gallons} = \frac{\text{Quarts}}{4} \]
Examples:
- 8 quarts = 8 ÷ 4 = 2 gallons
- 6 quarts = 6 ÷ 4 = 1.5 gallons
- 2 quarts = 2 ÷ 4 = 0.5 gallons
Fluid Ounces to Gallons
Since 128 fluid ounces equal one gallon, dividing any fluid ounce measurement by 128 yields gallons. This conversion helps when dealing with beverage containers, recipe scaling, or converting small volume measurements to larger gallon quantities.
\[ \text{Gallons} = \frac{\text{Fluid Ounces}}{128} \]
Examples:
- 128 fl oz = 128 ÷ 128 = 1 gallon
- 64 fl oz = 64 ÷ 128 = 0.5 gallons
- 32 fl oz = 32 ÷ 128 = 0.25 gallons
Convert Gallons to Cups & Water Weight
Gallons to Cups
One gallon equals 16 cups, making this conversion useful for recipe scaling and large-batch cooking. Multiplying gallons by 16 yields the cup equivalent, enabling easy translation between these common kitchen measurements.
\[ \text{Cups} = \text{Gallons} \times 16 \]
Examples:
- 1 gallon = 16 cups
- 0.5 gallons = 8 cups
- 2 gallons = 32 cups
Water – Gallons to Kilograms and Pounds
Water weight conversions prove essential for various applications from fitness tracking to industrial processes. One US gallon of water weighs approximately 8.345 pounds or 3.785 kilograms at standard temperature and pressure.
\[ \text{Pounds} = \text{Gallons} \times 8.345 \]
\[ \text{Kilograms} = \text{Gallons} \times 3.785 \]
Examples:
- 5 gallons water = 41.73 pounds or 18.93 kg
- 10 gallons water = 83.45 pounds or 37.85 kg
- 55 gallons water (drum) = 458.98 pounds or 208.18 kg
Comprehensive Gallon Conversion Chart
What is Gallon Conversion?
Gallon conversion translates volume measurements between gallons and other volumetric units within imperial, US customary, and metric systems. This fundamental skill enables accurate liquid measurement across diverse contexts—from filling fuel tanks and purchasing beverages to following recipes and calculating pool volumes. Understanding gallon relationships with quarts, liters, cups, and cubic measurements ensures measurement fluency regardless of which unit appears in instructions, labels, or specifications.
The gallon serves as a cornerstone measurement in American commerce and daily life. Gas stations price fuel per gallon, grocery stores sell milk by the gallon, paint comes in gallon containers, and water consumption tracking often uses gallons. Converting between gallons and other units prevents measurement errors, enables international recipe adaptation, facilitates comparison shopping, and supports practical problem-solving in countless real-world scenarios where volume measurements matter.
Gallon conversion complexity arises from multiple measurement systems and regional variations. While Americans work primarily with US liquid gallons, international contexts may reference metric liters or UK Imperial gallons. Converting confidently between these systems requires understanding conversion factors, recognizing which gallon definition applies, and applying appropriate mathematical relationships to maintain accuracy across borders, industries, and applications.
Gallon Conversion Formulae
Primary Conversion Formulas
\[ \text{Gallons} = \frac{\text{Liters}}{3.785} \]
\[ \text{Gallons} = \frac{\text{Quarts}}{4} \]
\[ \text{Gallons} = \frac{\text{Fl Oz}}{128} \]
\[ \text{Gallons} = \frac{\text{Cups}}{16} \]
\[ \text{Gallons} = \frac{\text{Cu In}}{231} \]
\[ \text{Gallons} = \text{Cu Ft} \times 7.48 \]
Uses of Gallon Conversion
Fuel and Automotive
Gas stations sell fuel by the gallon in the US while international markets use liters. Converting between units helps travelers understand fuel costs, calculate mileage efficiency, and compare prices across borders. Oil changes, coolant capacity, and other automotive fluids often specify gallons or quarts, requiring conversion for proper maintenance and fluid level monitoring.
Cooking and Baking
Large-scale cooking and commercial food preparation use gallons while recipes specify cups, quarts, or liters. Converting enables recipe scaling for catering, restaurant service, or family gatherings. Beverage preparation for parties, punch recipes, and bulk liquid ingredients all benefit from accurate gallon conversion to ensure correct proportions and sufficient quantities.
Pool and Aquarium Maintenance
Swimming pools and aquariums measure capacity in gallons while dimensions appear in feet or meters. Converting cubic footage to gallons calculates total volume for chemical dosing, filtration system sizing, and water replacement. Accurate volume knowledge ensures proper chlorine levels, salt concentrations, and other chemical treatments maintaining water quality and safety.
Gardening and Agriculture
Irrigation systems specify water delivery in gallons per minute while garden beds measure by cubic feet. Fertilizer mixing instructions use gallons while concentrate containers show fluid ounces. Converting between units ensures proper dilution ratios, prevents plant damage from over-concentration, and optimizes water usage for efficient, sustainable gardening and agricultural practices.
Household Management
Water heater capacity, washing machine usage, and daily water consumption tracking use gallons. Converting to liters helps understand metric-based efficiency ratings. Paint coverage calculations convert gallons to square feet. Humidifier and dehumidifier capacities, water softener salt requirements, and emergency water storage all involve gallon measurements requiring conversion for proper sizing and usage.
Commercial and Industrial
Manufacturing processes specify liquid volumes in various units requiring conversion. Shipping regulations measure container capacity in gallons. Chemical processing, brewing, and food production all use gallons alongside metric measurements. Accurate conversion ensures compliance with regulations, maintains product quality, and enables international trade across different measurement standards.
How to Use the Gallon Calculator?
Complete Usage Guide
Step-by-Step Instructions
- Select your starting unit from the "Convert From" dropdown menu (gallons, liters, quarts, etc.)
- Enter your measurement value in the input field
- Click the "Convert" button to calculate all equivalents
- View comprehensive results showing conversions to all supported units
- Results include gallons, liters, quarts, cups, fluid ounces, and more
Practical Tips
- Bookmark this calculator for quick kitchen and garage reference
- Double-check which gallon type (US or UK) your source uses
- Use decimal values for precise measurements (e.g., 2.5 instead of 2 1/2)
- For water weight conversions, remember temperature affects density slightly
- Keep common conversions memorized: 4 quarts = 1 gallon, 128 fl oz = 1 gallon
Frequently Asked Questions
1. How many liters are in a gallon?
One US gallon equals 3.785411784 liters (commonly rounded to 3.785 liters). This conversion applies to US liquid gallons, the standard for fuel, beverages, and liquid products in the United States. UK Imperial gallons contain 4.546 liters, approximately 20% more than US gallons.
2. How many quarts are in a gallon?
There are exactly 4 quarts in 1 gallon. This is one of the most fundamental US customary measurement relationships. Remembering "4 quarts = 1 gallon" enables quick mental conversions for cooking, automotive fluids, and beverage measurements without calculators.
3. How many ounces are in a gallon?
There are 128 fluid ounces in 1 gallon. Note: this refers to fluid ounces (volume), not weight ounces. The relationship 128 fl oz = 1 gallon helps convert beverage containers, recipe measurements, and bottle sizes to gallon equivalents for purchasing and portion planning.
4. How many cups are in a gallon?
One gallon contains 16 cups. This conversion proves essential for recipe scaling and large-batch cooking. To convert: gallons × 16 = cups. For example, 0.5 gallons = 8 cups, 2 gallons = 32 cups. This relationship helps when recipes specify cups but ingredients come in gallon containers.
5. How much does a gallon of water weigh?
One US gallon of water weighs approximately 8.345 pounds or 3.785 kilograms at room temperature (about 62°F/17°C). Water weight varies slightly with temperature—warmer water weighs less, colder water weighs more. For practical purposes, 8.34 pounds per gallon provides sufficient accuracy for most applications.
6. What's the difference between US and UK gallons?
A US gallon (3.785 liters) is smaller than a UK Imperial gallon (4.546 liters). UK gallons are approximately 20% larger. This difference matters when interpreting fuel efficiency (MPG), following UK recipes, or purchasing products from British sources. Always verify which gallon system your source uses to avoid measurement errors.
7. How many gallons are in a cubic foot?
One cubic foot equals approximately 7.48 gallons (precisely 7.48051948 gallons). To convert cubic feet to gallons, multiply by 7.48. This conversion helps calculate pool volumes, tank capacities, and water storage container sizes when dimensions are measured in feet but capacity needs expression in gallons.
8. How do I convert gallons to pints?
Multiply gallons by 8 to get pints (1 gallon = 8 pints). Since 1 gallon = 4 quarts and 1 quart = 2 pints, the relationship follows logically. For example, 2 gallons = 16 pints, 0.5 gallons = 4 pints. This conversion appears frequently in beverage measurements and recipe quantities.
9. Why does my pool calculator show different gallon amounts?
Pool calculators may show different results if they use actual water volume versus theoretical volume. Pools rarely fill to the absolute brim, depth varies throughout the pool, and shapes may not be perfect rectangles. Additionally, some calculators account for displacement from ladders, steps, and built-in features. Use conservative estimates for chemical dosing.
10. Can I use this calculator for dry measurements?
No, this calculator converts liquid volume measurements only. Gallons measure liquid volume, while dry ingredients require weight measurements (pounds, ounces by weight) or dry volume measurements (bushels, pecks). A gallon of flour doesn't weigh the same as a gallon of water. For dry ingredients, use appropriate weight-based conversions specific to each substance.