Sources and Methodology

US tablespoon

14.7868 ml per tablespoon. Source: USDA and the US system defined via the US fluid ounce (29.5735 ml), of which one tablespoon is half.

UK tablespoon

15 ml per tablespoon. Source: British Standards Institution (BSI). Standardised metric equivalent.

Australian tablespoon

20 ml per tablespoon. Source: Standards Australia (AS 1291). Established at metrication in 1974 for a clean 4:1 ratio with the 5 ml teaspoon.

Teaspoon (universal)

5 ml. Consistent across US, UK, Australia, Canada, and metric systems.

King Arthur Baking Ingredient Weight Chart

Primary source for flour types, sugars, and baking ingredients. URL: kingarthurbaking.com/learn/ingredient-weight-chart

USDA FoodData Central

Used for water, honey, oils, and syrups. URL: fdc.nal.usda.gov

Serious Eats (Kenji Lopez-Alt)

Salt density tests and kosher salt brand comparisons. URL: seriouseats.com

Diamond Crystal vs Morton kosher salt

Diamond Crystal: approximately 9 g per tablespoon (hollow pyramid crystals, Alberger process). Morton kosher: approximately 15 g per tablespoon (flat, dense crystals). Verified against Serious Eats salt tests and King Arthur Baking salt guides.

Table salt density

Approximately 18 g per tablespoon. Small, tightly packed NaCl crystals.

FDA Consumer Update on oral liquid dosing

The FDA has published consumer guidance noting that household teaspoons vary in volume and should not be used for liquid medicine. Use calibrated oral syringes. URL: fda.gov (search: Use Only the Dosing Device That Comes With Your Liquid Medicine)

American Academy of Pediatrics (AAP)

AAP recommends measuring children's liquid medicine in millilitres using a calibrated oral syringe. Published in Pediatrics journal and AAP consumer guidance.

Real-world quantity references

The cooking-context lines that appear under the converter (such as 'about the vanilla extract for a single-serve mug cake') are based on typical quantities from standard published recipes. They are intended as approximate guides only.

Rounding

All millilitre values are rounded to one decimal place. US tablespoon is rounded to 15 ml for practical kitchen use, though the precise value is 14.7868 ml.

Fraction display

Fractional teaspoon values (1/4, 1/2, 3/4, etc.) are approximated to the nearest common fraction within 5% tolerance. Values outside this tolerance are shown as decimals.