How this calculator works
A mass cannot determine a spoon volume without a density. Choose an ingredient and preparation, or enter a measured bulk density. Food presets use the gram quantities in King Arthur Baking's chart, interpreting a cup as a US customary cup. They are kitchen estimates that change with packing and product. The spoon definition itself is exact: 1 US tablespoon = 14.78676478125 mL. Water uses the approximate 1 g/mL convention described by USGS. Each preset also works in reverse.
Formula
US tbsp = mg / (1000 x density in g/mL x 14.78676478125). mg = US tbsp x 14.78676478125 x density x 1000. For all-purpose flour, the 120 g per US cup estimate gives 7500 mg per tablespoon; this ingredient factor is approximate.
Worked example
Using the flour preset, 15000 mg is approximately 2 US tablespoons. Using the honey preset of 21 g per tablespoon, half a tablespoon is approximately 10500 mg. The common-values table changes when you choose another ingredient.
Advertisement
Frequently asked questions
Is 1000 mg one tablespoon?
No. It is one gram. A tablespoon is a volume, and the mass fitting into it depends on the ingredient.
Which tablespoon is used?
The US customary tablespoon. A 15 mL metric tablespoon and a 20 mL Australian tablespoon are different volumes. For those, select mL as the input volume and enter 15 or 20 in reverse mode.
What if my ingredient is not listed?
Choose custom density and use a measured or supplier-provided bulk density. Use the actual preparation: whole nuts and ground nuts can fill the same spoon very differently.
Can this measure a medicine dose?
No. The food presets estimate kitchen quantities and do not describe a medicine concentration. Use the labelled measuring device and prescribed units.