How to Calculate a Dosage in Milliliters

A teaspoon equals roughly five milliliters.

With all medicines, whether prescription or nonprescription, you want to ensure that you are receiving or administering the proper dose. As many measurement units used in the United States are inconsistent with metric units employed abroad, this is particularly pertinent while traveling or when catering to foreign guests. The process involves some simple math conversions that you can easily perform. However, when in any doubt about medication, call your doctor.

Things You'll Need

• Dosage instrument (tsp.-, tbsp.- or ml.-based)
• Paper
• Pen or pencil
• Calculator (optional)

Instructions

1. Identify the unit. The most common metric unit used with medicines in much of the world is milliliters, a volume measurement. For most over-the-counter medicines in the United States, the corresponding measurement unit will be teaspoons or tablespoons (the former being more common).

2. Make the conversion to milliliters. One teaspoon is equal to 4.92892159 milliliters. Simply take the number of teaspoons and multiply it by an abbreviated 4.93:

   2 (tsp) x 4.93 = 9.86 (ml)

3. To convert back to teaspoons, all you need to do is reverse the operation and divide. Take the total number of milliliters and divide it by 4.93.

   19.72 (ml) / 4.93 = 4 (tsp)

4. If the dosage you want to convert to milliliters is in tablespoons, consider that the tablespoon in the United States is equivalent to three teaspoons, or approximately 14.79 milliliters. In Australia, however, a tablespoon is 20 milliliters.

Tips & Warnings

• While for most over the counter treatments .08 ml is not an enormous difference, always consult your doctor if you have questions or doubts about the dosage.

References

• Ask Numbers: Teaspoon(s) to Millimeter(s) Conversion
• CSGN Network: Kitchen Conversion Tables