One day, Adina woke up to find herself in the realm of ants. She saw a bunch of ants bringing her delicacies and drinks of exquisite taste. Time and time again, every day at mealtimes, these things would arrive, but always in the same amount. Adina grew bored quickly. So she hesitantly asked a few of her newfound friends why she was getting the same things in the same amounts every day. They told her it was a special diet the queen had decreed just for her; they had to serve a specific amount of each item. They weighed various goods, compiled a list, and presented it to the queen for approval before the menu was sent to the kitchens. So, Adina decided to go to the chef and asked her for the list.

Adina noticed an unusual unit of weight. Because the ants were but little creatures, they weighed their food in milligrams (mg) before serving. Unfamiliar with the new unit, she was perplexed. So, let’s help her!

## Definition of Milligram

**Milligram Unit**

Milligram (mg) is a unit of weight or mass in the International System of Units (SI). The abbreviation or symbol for milligram is “mg.”

**Milligram SI Prefixes**

The SI prefix of a milligram is “milli,” derived from the Latin word “mille,” meaning one thousandth.

**Milligram Size: What Is a Milligram Equal to?**

“Milli” means one thousandth. So, 1 milligram equals a thousandth of a gram or 0.001 gram. In other words, 1 gram $= 1000$ milligrams.

**Milligram Example**

In our day-to-day lives, we can find milligrams written on our medicines to depict their mass. Example: a 500 mg tablet.

Also, you can find the mass of the ingredients used in the making (say) a lotion or shampoo in milligrams or the nutritional information on food packaging.

## Milligrams and Other Units of Mass or Weight

**Milligrams and SI Prefixes**

Similar to the prefix “milli,” there are multiple prefixes used before “gram” in the metric system to form different units. Let’s see some of them.

- One milligram is 1/1000th of a gram.
- “Centi” means one-hundredth. So, one centigram is 1/100th of a gram.
- “Deci” means one-tenth. So, one decigram is 1/10th of a gram.
- Gram
- “Deca” means ten times. So, one decagram is 10 times a gram.
- “Hecto” means a hundred times. So, one hectogram is 100 times a gram.
- “Kilo” means a thousand times. So, one kilogram is 1000 times a gram.

**Milligram Conversion**

We can use the milligram chart given below for milligram conversion.

In the above chart, when we move towards the right-hand side, we keep multiplying with 10. Similarly, while moving towards the left, we keep dividing by 10.

## How Much Is a Milligram?

**1 Milligram in Metric Units**

**1 Milligram in Centigrams**

1 mg $= 1 \div 10$ cg (one place to the left) $= 0.1$ cg

**1 Milligram in Decigrams**

1 mg $= 1 \div (10 \times 10)$ dg $= 0.01$ dg

**1 Milligram in Grams**

1 mg $= 1 \div (10 \times 10 \times 10)$ g $= 0.001$ g

**1 Milligram in Decagrams**

1 mg $= 1 \div (10 \times 10 \times 10 \times 10)$ dag $= 0.0001$ dag

**1 Milligram in Hectograms**

1 mg $= 1 \div (10 \times 10 \times 10 \times 10 \times 10)$ hg $= 0.00001$ hg

**1 Milligram in Kilograms**

1 mg $= 1 \div (10 \times 10 \times 10 \times 10 \times 10 \times 10)$ kg $= 0.000001$ kg

**1 Milligram in US Customary Units**

**1 Milligram in Grains**

1 mg $= 0.0154$ grains

**1 Milligram in Ounces**

1 mg $= 0.000035$ oz.

**1 Milligram in Pounds**

1 mg $= 0.0000022$ lbs

## Fun Facts!

- A liter is a common non-SI unit of volume. The mass of 1 liter is 1 kg. Therefore, 1 mg weighs 1 ml (milliliter). Therefore, a milliliter of water weighs 1 mg.
- Carat is a common unit of mass used to weigh pearls and gemstones. One carat is 200 mg or 0.007 oz.

- A mosquito weighs around 2.5 mg.
- An adult housefly weighs around 21.4 mg.
- Your coffee has somewhere around 27–200 mg of caffeine.
- Our body requires approximately 1 mg Vitamin B1, 1.2 mg Vitamin B2, 75–90 mg Vitamin C, 8–18 mg iron, and 1000 mg calcium daily.

## Things That Weigh 1 mg

Here are some common objects weighing 1 mg:

- A small snowflake
- 1 mg liquid
- 005-carat pearl
- A grain of salt/sand

## Solved Examples

**1. A group of ants is hunting for food. A worker ant found a few breadcrumbs weighing 300 mg, a few grains of sugar weighing 30 cg, and tiny cake pieces weighing 4 dg. How much is the total weight of food found by the worker ant?**

**Solution:**

From the conversion chart, 30 cg $= 30 \times 10$ mg

$= 300$ mg

Similarly, 4 dg $= 4 \times 10 \times 10$

$= 400$ mg

Therefore, the total weight of the food found by the worker ant

$= 300 + 300 + 400$ mg

$= 1000$ mg

$= 1$ g

**2. Convert 3 hg into mg.**

**Solution:**

From the conversion chart, 3 hg $= 3 \times 10 \times 10 \times 10 \times 10 \times 10$ mg

$= 3 \times 100,000$ mg

$= 300,000$ mg

**3. Arrange the following in descending order:**

**0.004 g sugar grains****0.0001 hg sand****3 ml syrup****200 mg bread crumbs****0.0154 grains salt**

**Solution:**

From the conversion table, $0.04$ g $= 0.004 \times 10 \times 10 \times 10$ mg

$= 40$ mg……(1)

$0.0001$ hg $= 0.0001 \times 10 \times 10 \times 10 \times 10 \times 10$ mg

$= 10$ mg……(2)

We know that 1 ml $= 1$ mg.

So, 3 ml $= 3$ mg……(3)

200 mg breadcrumbs (given)……(4)

We know that 0.0154 grains $= 1$ mg…… (5)

Arranging in descending order, $(4) \gt (1) \gt (2) \gt (3) \gt (5)$

200 mg breadcrumbs $\gt 0.004$ g sugar grains $\gt 0.0001$ hg sand $\gt 3$ ml syrup $\gt 0.0154$ grains salt.

**4. Kohinoor weighs 105.6 carats. What is its weight in mg?**

**Solution: **We know that 1 carat $= 200$ mg

So, 105.6 carats $= 105.6 \times 200$ mg

$= 21,120$ mg

**5. An ant carries a 3 dg of breadcrumbs. On the way, due to heavy winds, 70 mg of breadcrumbs fall off. The ant decides to carry the remaining breadcrumbs to the hill. How much is the total weight of food the ant carries to its hill?**

**Solution:**

From the conversion chart, 3 dg $= 3 \times 10 \times 10$ mg

$= 300$ mg

70 mg of breadcrumbs fall off due to heavy wind.

So, the weight of the remaining breadcrumbs $= 300 – 70$ mg

$= 230$ mg

## Practice Problems

## Milligram

### Express 0.0001 kg in mg.

$0.0001$ kg $= 0.0001 \times 10 \times 10 \times 10 \times 10 \times 10 \times 10$ mg

$= 100$ mg

### Arrange the following in ascending order:

(1) 3-carat diamond

(2) 0.2 g grains of sand

(3) 5 ml water

(4) 20 mg breadcrumbs

One carat $= 200$ mg.

So, 3 carats $= 3 \times 200$ mg

$= 600$ mg…… (1)

0.2 g $= 0.2 \times 10 \times 10 \times 10$ mg (from the conversion chart)

$= 200$ mg…… (2)

We know that 1 ml $= 1$ mg.

So, 5 ml $= 5$ mg…… (3)

20 mg bread crumbs (given)…… (4)

Arranging in ascending order, $(3) \lt (4) \lt (2) \lt (1)$.

### Express 50,000 mg in dag.

From the conversion chart, 50,000 mg $= 50,000 \div (10 \times 10 \times 10 \times 10)$

$= 5$ dag

## Frequently Asked Questions

**Which is bigger—gram or milligram?**

A gram is bigger than a milligram. 1 gram $= 1000$ mg. So, 1 gram is 1000 times bigger than a milligram.

**What does a milligram measure?**

A milligram is a unit in the SI system used to express small objects’ mass.

**Is a milligram smaller than a microgram?**

Micro means one-millionth. So, a microgram is 1/1,000,000th of a gram. On the other hand, a milligram is 1/1000th of a gram. Therefore, a microgram is 1000 times smaller than a milligram.

**How many milligrams of water are there in a teaspoon?**

There is 4929 mg of water in a teaspoon.

**Why do we rarely use mg for weighing things in daily life?**

A milligram is a small unit of weight, just a tiny fraction of three of the smallest units of mass in the US customary system**—**grains, pounds, and ounces. Therefore, its daily application is limited to things like medicine dosage.