This volume converter converts liters, gallons, milliliters, cups, fluid ounces, quarts, pints and cubic units in both directions — US liquid measures, with the imperial differences flagged where they bite.
Two Gallons Exist — Choose Carefully
The US gallon is 3.785 L; the UK imperial gallon is 4.546 L — 20% larger, because Britain redefined its gallon in 1824 and America kept the older wine gallon. This converter carries both, labeled, because fuel economy, aquarium and brewing math cross the Atlantic constantly. Kitchen volumes (cups, tablespoons) are US; for cooking by weight, our Cups to Grams Converter finishes the job, and volumes from dimensions belong to the Volume Calculator. Part of our Conversion Calculators collection.
Quick Reference
| 1 unit | = liters | 1 unit | = liters |
|---|---|---|---|
| 1 US gallon | 3.785 | 1 US cup | 0.237 |
| 1 UK gallon | 4.546 | 1 US fl oz | 0.0296 |
| 1 cubic meter | 1,000 | 1 cubic foot | 28.32 |
| 1 liter | 33.81 US fl oz | 1 tablespoon | 0.0148 (14.8 mL) |
Worked Examples (Verified)
- A 10-gallon aquarium = 37.85 liters (and about 84 lb of water alone — stands must be rated)
- A 750 mL wine bottle = 25.4 fl oz = five 5-oz glasses, generously measured
- 1 cubic meter of water = 264.2 US gallons and weighs a metric tonne — the system was designed so these numbers rhyme
Related Tools
- Volume Calculator — volume from shapes
- Cups to Grams Converter — kitchen volumes to weights
- Conversion Calculators — the full collection
Frequently Asked Questions
How many liters are in a gallon?
US gallon: 3.785 liters. UK imperial gallon: 4.546 liters. Always check which gallon a spec uses — engine oil, fuel and fish tanks cross borders.
How many cups are in a liter?
About 4.23 US cups (1,000 ÷ 236.6). Recipes convert cleanly at 4 cups + a generous splash per liter.
Is a fluid ounce the same as an ounce?
No — fluid ounces measure volume, ounces measure weight. They coincide only for water (1 fl oz of water ≈ 1.04 oz by weight, close but not equal), which is why cooking by weight beats both.
How many milliliters is a tablespoon?
US tablespoon: 14.79 mL (15 mL on nutrition labels); Australian tablespoon: 20 mL — the one international recipe trap bigger than the gallon split.
What is a cubic meter in gallons?
264.2 US gallons. A cubic meter (1,000 L) is the utility billing unit for water in most of the world — about what a household uses every few days.
Is this volume converter free?
Yes — free, instant, no sign-up.