Converting Milligrams of Sodium to Teaspoons of Salt: A Kitchen Chemistry “Health Watch”

Watch That Sodium: When you make a home-cooked meal for your family, you want it to be nutritious, tasty, and healthy. You can easily do this by starting from scratch and being careful what you add by way of ingredients. One ingredient you will want to watch is table salt and other substances that contain sodium, such as monosodium glutamate (MSG).

Can’t Have Home Cooked? You Need a Conversion Formula!

Since most of can’t always eat home-cooked meals, but we rely on store-bought preprocessed foods, and sodium content is not listed in a completely user-friendly manner, I provide here a conversion calculation that converts milligrams of sodium into its equivalent teaspoons of salt.

If you don’t want to see how I arrived at the correct equation, but only want to know the conversion, feel free to jump down now to the last subheading of this article.

Sodium on the chemist’s periodic table of the elements, has a molecular weight of 23.0. There is no need to get into the details of what this means. Suffice it to recall that number for the present.

Now the kind of salt people eat on food, also called sodium chloride or table salt, is a combination of one chlorine atom for each atom of sodium, NaCl, where Na is the sodium and Cl is the chlorine. The molecular weight of chlorine is 34.5. Thus salt, sodium chloride, has a molecular weight of (1) sodium + (1) chlorine = 23.0 + 34.5 = 57.5.

Let’s try out a simple conversion. Say a serving of corn contains 500 mg (1 milligram = 0.001 gram¹) of sodium. If all the sodium in the corn is from sodium chloride, how much sodium chloride is there in the corn? We lay out the equation:

> 500 mg of sodium x 57.5/23.0 = 1250 mg of salt (that was in the corn).

Good! But how many teaspoons is 1250 mg of salt? A teaspoon is not a unit of weight, but of volume. A teaspoon holds a specific volume of whatever is put into it. The official teaspoon holds 5 ml (1 milliliter = 0.001 liter) of liquid. An equation for density says,

> ml of granulated salt = (Mass in grams/Density in g/ml)

Finally, the density of granulated salt in grams/milliliter is about 1.25. Thus,

> milliliters of salt = (1.25/1.25) = 1.0 milliliters

Since there are 5 milliliters per teaspoon,

> teaspoons of salt = 1.0/5 = 0.2 teaspoons

This is just a fifth of a teaspoon of salt in one serving of corn. If you will eat more than one serving, you have to increase the amount of salt in your calculation accordingly. Thus, if you are going to eat three servings of corn, you will consume about 3/5 of a teaspoon of salt.

The Final Formula!

In closing, remember: Number of Teaspoons of Salt = (milligrams of sodium x 0.0005)

Don’t forget that if you are calculating on the basis of milligrams of sodium per serving, you must take into account how many servings you will be consuming to get an accurate figure.

Lastly note that the American Heart Association says that a healthy individuals can get by with well under a teaspoon of salt per day.

¹ the gram unit is abbreviated “g.”