How many teaspoons is 90mg?

You can't directly convert milligrams (mg) to teaspoons (tsp) because they measure different things:

* Milligrams (mg): Measure weight or mass.

* Teaspoons (tsp): Measure volume.

To convert between these units, you need to know the density of the substance you're measuring.

Here's why it matters:

* 90 mg of salt would take up less volume than 90 mg of sugar.

* 90 mg of water would have a different volume than 90 mg of oil.

To accurately convert, you need to know:

1. What substance you are working with.

2. The density of that substance.

Example: If you wanted to convert 90 mg of salt to teaspoons, you'd need to know the density of salt. Then, you could use the following formula:

Volume (in tsp) = Mass (in mg) / (Density * 1000) * 4.93

Where:

* 1000 is the conversion factor from mg to grams

* 4.93 is the approximate conversion factor from milliliters to teaspoons.

It's important to note: This conversion would only be accurate for salt. You'd need to find the density of any other substance to perform a similar conversion.