If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Basic geometry and measurement

### Unit 5: Lesson 2

Converting units of mass

# Metric units of mass review (g and kg)

Review the size of grams and kilograms and how to convert between the two.  Then, try some practice problems.

## Metric units of mass

Mass is used to measure the weight of an object. For example, you are measuring the mass of your body when you step on to a scale.
In the metric system of measurement, the most common units of mass are the gram and kilogram.

### How much is a gram?

A small paperclip has a mass of about 1 gram:
A paperclip.

### How much is a kilogram?

A wooden baseball bat has a mass of about 1 kilogram:
A baseball bat.

## Practice set 1: Estimating mass

Problem 1A
Identify the most reasonable unit to measure the mass of a pack of gum.

Want to try more problems like this? Check out this exercise.

## Converting kilograms to grams

1, start text, space, k, i, l, o, g, r, a, m, end text, equals, start color #1fab54, 1000, end color #1fab54, start text, space, g, r, a, m, s, end text
To convert kilograms to grams we multiply the number of kilograms by start color #1fab54, 1, comma, 000, end color #1fab54.
Example:
start color #11accd, 8, end color #11accd, start text, space, k, i, l, o, g, r, a, m, s, end text, equals, start color #11accd, 8, end color #11accd, times, start color #1fab54, 1000, end color #1fab54, equals, start color #11accd, 8, end color #11accd, start color #1fab54, 000, end color #1fab54, start text, space, g, r, a, m, s, end text

## Converting grams to kilograms

1, start text, space, g, r, a, m, end text, equals, start fraction, 1, divided by, start color #1fab54, 1000, end color #1fab54, end fraction, start text, space, k, i, l, o, g, r, a, m, end text
To convert grams to kilograms we divide the number of grams by start color #1fab54, 1000, end color #1fab54.
Example:
start color #ff00af, 9, end color #ff00af, start text, space, g, end text, equals, start fraction, start color #ff00af, 9, end color #ff00af, divided by, start color #1fab54, 1000, end color #1fab54, end fraction, equals, start color #ff00af, 9, end color #ff00af, divided by, start color #1fab54, 1000, end color #1fab54, equals, start color #6495ed, 0, point, 009, end color #6495ed, start text, space, k, g, end text

## Practice set 2: Converting units of mass

Problem 2A
Convert.
7 kilograms equals
grams

Want to try more problems like this? Check out these exercises:
Convert larger units to smaller units
Converting between units

## Want to join the conversation?

• i always get confused with the milligrams and kilograms. How do you tell the difference
• In the metric system, "milli" means 1/1,000 and "kilo" means 1,000. This means that a milligram is 1/1,000 of a gram, and a kilogram is 1,000 grams.
So a kilogram is much heavier than a milligram; in fact, a kilogram is a million times as heavy as a milligram!
• how can you convert kilograms to grams or any type of measurement in the metric system in general
• you have to figure out if you need to either multiply or divide by multiples of 10
for example, if you go from grams to kilograms, you divide by 1000
if you go from kilograms to grams, you multiply by 1000
that's it!
• how many grams are in a kilogram
• There are 1,000 milligrams in a gram.
There are 1,000 grams in a kilogram.
• can you explain the khdbdcm
• KHDBDCM is short for Kilo, Hecto, Deka, Base, Deci, Centi, Milli where base means metre,litre etc.depending upon the thing we are measuring.Kilo, Hecto, Deka, Base, Deci, Centi, Milli are units of measure to indicate a multiple or fraction of the unit.
Hope it helps :)
• How do you convert 5 grams to kilograms when there is not at least 1000 grams?How do you now the exact decimal?Please explain the formula🥺.
• Hi, this is where decimals come into play, since you do not have 1000 grams, you know you have at least 5 grams of a kilogram. In other words, you still convert the grams into whatever amount of a kilogram regardless if you have 1000 or not, you would have 0.005 of a kilogram. Hope this helped 👍
• How do you guys get your learning so easy for kids like me
• Honey, you just need to understand. Ask the teacher questions if you have them, there is no need to be ashamed. If you put it this way: which is more embarassing: asking a question, or getting an F
• will it tell me if i have passed the lesson all the way
• It shouldn't. You need to answer 6 questions.
• I don´t really understand grams and kilograms. how could you use the decimals?
• A "gram" is the standard unit for mass. "Kilogram" is just 1 000 x the mass of the gram.
To multiply by 1 000, all you have to do is move the decimal point to the right 3 times because there are 3 zeros, and to divide by 1 000 you move it 3 times to the left.
For example:
3 kilograms = 3 000 grams
3 grams = 0.003 kilograms