Millimeters are one of the measurement units that is frequently used in mathematics. It is used by engineers, surveyors, manufacturers, industrialists, and even by students at school. A millimeter is a unit of length. The prefix ‘milli’ means one thousand in Latin. Hence, one millimeter is one-thousandth of a meter. Here are the other key points that you must keep in mind:

- The symbol of millimeters is mm.
- There are ten millimeters in one centimeter.
- One millimeter is equal to 1000 micrometers.
- One millimeter is equal to 1 000 000 nanometers.
- One inch is equal to 25.4 millimeters.
- One millimeter is equal to 0.03937 inches.

**What does a millimeter mean?**

The meter is defined as the length of the path traveled by light in a vacuum during a time interval of 1/299792458 of a second. This definition has been followed since 1983 though it was originally recorded in 1800-10 in French.

A millimeter is 1/1000 of a meter. Hence, a millimeter is a distance traveled by light in 1/299792458000 of a second. It is sometimes denoted as ‘mili’ and represented as mm. The term ‘mili’ confuses the US, which traditionally means a thousandth of an inch. The actual millimeter is 0.03937 of an inch.

**Facts about millimeters **

- The metric ruler, which students carry for their school as a part of their stationery, has the smallest unit of measurement, millimeters. If the scale is high-quality, then the probability is it might carry up to 0.5 mm.
- Microwaves, having a frequency of 300GHz, have a wavelength of 1 mm. These wavelengths are used in data transmission that has the potential to transfer the data at 10 gigabytes per second.
- The smallest distance the human eye can resolve is around 0.02 to 0.04 mm, near about the width of a human hair.
- A sheet of paper has a thickness of 0.07 mm that can be as thick as 0.18 mm. An ordinary paper has a thickness of about 0.1 mm.

**Milliliters to Liters**

After understanding what a millimeter means, let us study how to convert millimeters to liters. Since a millimeter is a unit of length and a liter is a unit of capacity, the correct unit to convert to a liter will be cubic millimeters, denoted by the capacity unit.

1 cubic meter = 1000 liters

1 cubic meter = 1000 000 000 cubic millimeter

Hence, 1 liter = 1000 000 cubic millimeter

**Milliliters to Ounces **

Now, let us learn how many millimeters in an ounce are there. If you wonder how many millimeters in an ounce are there, the answer is 29.573. This is the liquid ounce of the US. The UK ounce will differ a bit.

1 cubic meter, the unit of volume, is 1000 000 000 cubic millimeters. Hence, 1 cubic meter is equal to 33814.022 oz. Other conversion units are given below:

- 1 milliliter to oz = 0.03381 oz
- 10 milliliter to oz = 0.33814 oz
- 20 milliliter to oz = 0.67628 oz

**Liters to Milliliters **

Liter and milliliter are the units of volume. Hence, 1 liter is equal to 1000 milliliter. The other conversions of the volume units are given below in the table.

Kiloliter | 1000 liter (l, small letter of L) |

Hectaliter | 100 l |

Decaliter | 10 l |

Liter | l |

Deciliter | 0.1 l |

Centiliter | 0.01 l |

Milliliter | 0.001 l |

**How many milliliters are in a teaspoon? **

A teaspoon is a culinary measure, which is ⅓ of a tablespoon. A US teaspoon has 4.92892 milliliters in a teaspoon. It is also referred to as a flat spoon. A teaspoon is used to stir tea, measure sugar, and play games such as spoons and many other things. However, the unit of conversion will change for the UK teaspoon.

**Conversion tables **

The various conversion tables will help you quickly get millimeters to the desired unit.

Kilometer | 1000 m |

Hectometer | 100 m |

Decameter | 10 m |

Meter | m |

Decimeter | 0.1 m |

Centimeter | 0.01 m |

Millimeter | 0.001 m |

Meter (m) | Millimeter (mm) |

0.01 m | 10 mm |

0.1 m | 100 mm |

1 m | 1000 mm |

2 m | 2000 mm |

3 m | 3000 mm |

5 m | 5000 mm |

10 m | 10000 mm |

20 m | 20000 mm |

50 m | 50000 mm |

100 m | 100000 mm |

Millimeters | Inches |

1 mm | 3/64 inch |

2 mm | 5/64 inch |

3 mm | ⅛ inch |

4 mm | 5/32 inch |

5 mm | 13/64 inch |

6 mm | 15/64 inch |

7 mm | 9/32 inch |

8 mm | 5/16 inch |

millimeter to kilometer (km) | 0.000001 |

millimeter to meter (m) | 0.001 |

millimeter to decimeter (dm) | 0.01 |

millimeter to centimeter (cm) | 0.1 |

millimeter to micrometer (micron) | 1,000 |

millimeter to nanometer (nm) | 1,000,000 |

millimeter to ångström | 10,000,000 |

millimeter to league | 0.0000002071 |

millimeter to a mile (mi) | 0.0000006214 |

millimeter to land | 0.0000006214 |

millimeter to furlong | 0.000004971 |

millimeter to bolt | 0.00002734 |

millimeter to chain | 0.00004971 |

millimeter to pole | 0.0001988 |

millimeter to the rod (rd) | 0.0001988 |

millimeter to perch | 0.0001988 |

millimeter to the yard (yd) | 0.001094 |

millimeter to foot (ft) | 0.003281 |

millimeter to feet and inches (x’y”) | 0.03937″ |

millimeter to span | 0.004374 |

millimeter to hand | 0.009843 |

millimeter to inch (in) | 0.03937 |

millimeter to line | 0.4724 |

millimeter to mil | 39.37 |

millimeter to microinch | 39,370 |

millimeter to furlong | 0.000004971 |

millimeter to Ramsden’s (engineers’) chain (ch) | 0.00003281 |

millimeter to Gunter’s (surveyors’) chain (ch) | 0.00004971 |

millimeter to Gurley’s chain (ch) | 0.00009942 |

millimeter to Gunter’s (surveyors’) pole | 0.0001988 |

millimeter to Gunter’s (surveyors’) yard | 0.001094 |

millimeter to Ramsden’s (engineers’) link | 0.003281 |

millimeter to Gunter’s (surveyors’) link | 0.004971 |

millimeter to Gurley’s link | 0.004971 |

millimeter to Gunter’s (surveyors’) foot (ft) | 0.003281 |

millimeter to the nautical league (Naut. league) | 0.00000018 |

millimeter to a nautical mile (Naut. mi) | 0.00000054 |

millimeter to cable length (cbl) | 0.0000054 |

millimeter to fathom (fath) | 0.0005468 |

millimeter to US nautical mile | 0.0000005396 |

millimeter to US fathom (fath) | 0.0005468 |

millimeter to US cable length | 0.000004557 |

**Understanding millimeters by examples **

**Example 1: Convert 50 cm to mm. **

**Solution:** We know, 1 cm = 10 mm. Therefore, 50 cm = 50 x 10 mm = 500 mm.

Hence, 50 cm is equal to 500 mm.

**Example 2: Convert 6790 millimeters to meters.**

**Solution:** We know that 1 meter = 1000 millimeters. We need to set up the conversion so that the desired unit will be canceled out. In the question mentioned above, we need meters in the end. Hence,

Distance in m = distance in mm x 1 m / 1000 mm

Distance in m = 6790 / 1000 m

Distance in m = 6.790 m.

**Example 3: How many millimeters are there in 6000 liters?**

**Solution:** We know, 1 cubic millimeter is equal to 10^{-6} liters.

In other words, 1 liter is equal to 10^{6} cubic millimeters. Therefore, 6000 liters is equal to

6000 liter x 10^{6} = 6000 x 10^{6} millimeters.

Note: Here is a table for your reference for other values of liters

1 Liter = 1000000 Cubic millimeters | 10 Liters = 10000000 Cubic millimeters | 2500 Liters = 2500000000 Cubic millimeters |

2 Liters = 2000000 Cubic millimeters | 20 Liters = 20000000 Cubic millimeters | 5000 Liters = 5000000000 Cubic millimeters |

3 Liters = 3000000 Cubic millimeters | 30 Liters = 30000000 Cubic millimeters | 10000 Liters = 10000000000 Cubic millimeters |

**Example 4: Convert 500 milliliters to ounces. **

**Solution: **We know that 1 fluid ounce is equal to 29.573 milliliters. Therefore, to convert mm to the ounce, you should divide 500 by 29.573.

Therefore, the value will be 16.907 fluid ounces.

**Example 5: Jelly’s friend asked her to measure the length of the showpiece kept in the drawing-room. Jelly took out a ruler that had millimeter markings. She found out the length of the showpiece was 39 millimeters. But her friend wanted to find the length of the showpiece in decimeters. What is the equivalent length in decimeters?**

**Solution: **The length of the showpiece was 39 millimeters. Jelly’s friend wants her to find the length in decimeters. So, let us convert millimeters to decimeters.

We know, that 1 millimeter is equal to 0.01 decimeters.

Hence, 39 millimeters will be equal to 0.01 x 39 = 0.39 decimeters.

Therefore, 39 millimeters is equal to 0.39 decimeters.

**Practice questions based on millimeters **

Q1. Choose the right answer for the given question: Convert 60 mm to cm.

- 0.6 cm
- 6 cm
- 60 cm
- 600 cm

Q2. Brett wanted to measure the side of a cube using a ruler. However, his ruler only had millimeter markings. He found the side length was 5.7 mm. But his teacher asked him to find the length in decameters. Can you help him do the conversions?

Q3. Convert the following as indicated:

- 456 cm to mm
- 7903 mm to an ounce
- 2345 teaspoon to mm
- 7823 millimeters to liters
- 2310 liters to millimeters