Skip to Content

Common Measurement Conversions

Written by C. Fookes, BPharm on Oct 11, 2017.

There are several measurement systems in use around the world and it can be daunting trying to convert a foreign measurement into one you are familiar with. To add to the confusion, some abbreviations for these measurements sound similar, yet the quantity may differ by a thousand. This article explains some of the more common conversions and abbreviations.

Measurement conversions: Liquids

How many teaspoons in a tablespoon? How many ml in a teaspoon? If you a giving any type of liquid medicine, you may be seeking the answers to these questions.

But the answer may not be as straightforward as saying one teaspoon equals 5mL. Using a kitchen spoon to measure the dose of a medicine is NOT a good idea unless it has been properly calibrated and has been sold as a kitchen measure. Teaspoons and tablespoons are NOT official measurements and most of the silverware and cutlery that you buy to eat with has not been standardized to the same volume, and actual teaspoon volumes may range from 2.5mL to 7mL. Measuring a dose with the cutlery you eat with will likely result in either an underdose or an overdose of the medicine.

Which is why you should always use a dosing cup, syringe, or measuring spoon. These are often supplied free with liquid medicines, but, if not, can be bought from a pharmacy and most supermarkets. Always use a properly calibrated measuring device to measure liquid medicines.

Note: Fluid ounces are a measure of volume while ounces are a measure of weight.

Quantity Conversion
½ teaspoon 2.5mL
1 teaspoon 5mL
2 teaspoons 10mL
½ tablespoon 7.5mL
1 tablespoon 15mL
3 teaspoons 1 tablespoon
1 litre 1000mL
1 fluid ounce 30mL*
1 pint 473mL*
1 gallon 3785mL*
* Approximately

Abbreviations

  • Teaspoon = tsp
  • Tablespoon = Tbsp or Tb
  • Millilitre = mL
  • Litre = L
  • Fluid ounce = fl oz
  • Pint = pt
  • Gallon = gal

Measurement conversions: Solids

How many mcg in a mg? How many mg in an oz? Measurement conversions for solids can be confusing, particularly when many of the units sound the same.

Quantity Conversion
1000 micrograms 1 milligram
1000 milligrams 1 gram
1000 grams 1 kilogram
1 kilogram 2.2 pounds
1 ounce 28,300 milligrams
1 ounce 28.3 grams
1 pound 16 ounces
1 pound 454 grams
1 pound 0.45 kilograms
1 stone 14 pounds
1 stone 6.35 kilograms

Abbreviations

  • Microgram = mcg (may also be written µgm)
  • Milligram = mg
  • Gram = gm
  • Kilogram = kg
  • Ounces = oz
  • Pounds = lbs

Measurement conversions: Temperature

The Fahrenheit scale for temperature is only used in the United States and its associated colonies, although Canada still retains it as a supplementary scale.

To convert Fahrenheit to Celsius, take the Fahrenheit temperature and subtract 32, then multiply this number by 5, then divide the answer by 9 to obtain the temperature in degrees Celsius.

To convert Celsius to Fahrenheit, take the Celsius temperature and multiply it by 1.8, then add 32 to obtain the temperature in degrees Fahrenheit.

The Celsius and Fahrenheit scales meet at -40°. Above -40°, Fahrenheit temperatures are always higher than corresponding Celsius temperatures, and below -40°, Fahrenheit temperatures are lower than the corresponding Celsius temperatures.

Temperature Conversion
0°C 32°F
-17.8°C 0°F
-40°C -40°F
30°C 86°F
100°C 212°F

Abbreviations

  • Celsius = C
  • Fahrenheit = F

See Also:

Sources

Hide