Volume Measurement Guide — Liters, Gallons, Cups & ml

By Unitafy · March 2026 · 5 min read

Volume measurement matters in cooking, chemistry, medicine, and fuel. The confusion between metric (liters, ml) and US customary (cups, gallons, fluid ounces) systems trips up even experienced cooks.

Metric Volume Units

Liter (L) — The standard metric unit. 1 liter of water weighs exactly 1 kg. A standard water bottle is 500ml (half a liter). Most countries use liters for fuel.

Milliliter (ml) — 1/1000 of a liter. Used for medicine doses, small cooking amounts, and beverages. 1 ml of water weighs 1 gram.

US Customary Volume Units

US Cup = 236.6 ml. American recipes use cups. Note: the Australian metric cup = 250 ml, so adjust when following Australian recipes.

US Tablespoon (tbsp) = 14.79 ml. 1 cup = 16 tablespoons.

US Teaspoon (tsp) = 4.93 ml. 1 tablespoon = 3 teaspoons.

US Gallon = 3.785 liters. US fuel is sold in gallons. UK imperial gallon = 4.546 liters (different!).

Quick Cooking Conversion Table

US MeasuremlLiters
1 teaspoon4.930.005
1 tablespoon14.790.015
¼ cup59.10.059
½ cup118.30.118
1 cup236.60.237
1 pint473.20.473
1 quart946.40.946
1 gallon37853.785

🍳 Cooking tip: When converting American recipes to metric, use these approximations: 1 cup ≈ 240 ml, 1 tbsp ≈ 15 ml, 1 tsp ≈ 5 ml. Simple enough to remember!