The Australian Tablespoon: 4 Teaspoons, Not 3
Updated 17 April 2026
In Australia, 1 tablespoon = 20 ml = 4 teaspoons. In the US and UK, 1 tablespoon = 15 ml = 3 teaspoons. The teaspoon is 5 ml in all three countries. If you cook with recipes from different countries, this 33% difference in tablespoon size can noticeably change a recipe outcome, especially in baking.
Country-by-Country Comparison
Why Australia chose 20 ml
When Australia completed its metrication in the 1970s, the Standards Association of Australia standardised the tablespoon at 20 ml. The reasoning was mathematical elegance: 20 ml divided by 5 ml (one teaspoon) gives a clean ratio of 4:1. The US and UK retained the older 15 ml tablespoon, which had historical roots in apothecary (pharmaceutical) measures based on the fluid dram system. The result is that every country uses the same 5 ml teaspoon, but the tablespoon differs. Recipes that specify tablespoons without naming a country can mean slightly different amounts.
Adjusting US/UK Recipes for Australian Tablespoons
When using an Australian tablespoon (20 ml) to measure a US recipe quantity, use less. Or substitute with teaspoons, which are the same size everywhere.