Relationship to teaspoon and fluid ounce[edit] In most regions (including the US, UK, most Commonwealth countries, East Asia and the Philippines), one tablespoon equals three teaspoons. In these regions, one tablespoon is approximately 15 ml, which is about 1⁄2 US fl oz. In some places like the US, the tablespoon was historically defined as 1⁄2 US fl oz (2 tbsp. = 1 US fl oz). In Australia a tablespoon is defined as four teaspoons (20 ml). Victorian and Edwardian era tablespoons used in the UK are often 25 ml or sometimes larger. They are used only for preparing and serving food, not as part of a place-setting.