An inch is defined as one twelth (1/12th) of a foot and used to measure small distances like the length of a pencil or the width of a book. Millimeters are used in the fashion industry for jewelry and fabric widths. Millimeters are also used in meteorology to record rainfall or snowfall. The M is also seen with an overstrike or overbar to represent that the preceding number should be multiplied by 1000. MM (also seen with overstrikes) means that the preceding number should be multiplied by 1000 and again by 1000 (i.e. 1,000,000).

## Convert Millimeters to Centimeters

A larger cylinder will hold more water, but it has a larger opening to collect rain, so the measured rainfall is the same in either case. It is also not necessary to talk about volume of water (eg cubic millimeters, liters etc) to understand this. You would only be converting to volume in order to convert back to depth later. It is the amount of rain that it takes to cover the ground X milimeters deep. It is normally measured in 24 hours and is measured each morning at a fixed time like 0900. Roman numerals are often used in accounting to help abbreviate and designate numbers.

## Why is one million dollars abbreviated as $1MM instead of just $1M?

We have to multiply the length by 10 every time we move from left to right. Also, for each time we move from left to right, we must divide the length by 10. $1k representing $1,000 is grammatically incorrect, but has become acceptable to use what does mm mean in informal situations like news headlines. I can imagine though that among Meterologists the sentence “Hong Kong reports 3 mm of rain” is taken to mean “The Hong Kong Observatory reports 3 mm of rain”, and equivalently for other places.

## The average length of a red ant is 5 mm. Express it in meters.

It means that during the rain event (which may last a minute, an hour, a day), one square meter of ground was filled with water up to a height of 3mm. Therefore, if the rainfall is 1 mm, every square meter receives 1 liter of rain water. Inches are imperial measurements that are normally used in the United States and United Kingdom. It is often necessary to convert inches to millimeters when following instructions of specifications in a unit unfamiliar to you. “Millimeter” is a unit of length that equals one-thousandth of a meter.

We have measures like meters and kilometers to express bigger distances, like the distance between two cities, the height of mountains, lengths of rivers, etc. However, the length of the wheat grain, the size of an ant, the thickness of a paper, etc., are some measures we find difficult to express in bigger units of measurement like meters. One common design is to have a funnel with a large area at the top feed into a narrower container below.

- If 1,000 multiplied by 1,000 equals 1,000,000, and 1,000 equals M, then we can use the abbreviations to create calculations.
- Therefore, if the rainfall is 1 mm, every square meter receives 1 liter of rain water.
- There are two formulas to convert mm to m, either multiply the value of mm with 0.001 or divide it by 1000.
- The Hindu – Arabic numeral system is what we have used ever since.
- However, the length of the wheat grain, the size of an ant, the thickness of a paper, etc., are some measures we find difficult to express in bigger units of measurement like meters.

We often find the abbreviation (mm) on financial statements, which stands for millions. Unfortunately, this practice can occasionally cause confusion within the financial industry as multiple numerical abbreviations are used interchangeably within society. I will address the aspects of the question that relate to how rainfall is measured and the measurement period. Given any container with straight sides, 3 millimeters of rainfall will fill up that container to 3 millimeters in depth.

## mm to inches (Millimeters to Inches) conversion calculator

There would be approximately 1,000 sand grains lined up along a meter stick at 1mm each. The intensity or duration differed from place to place, the ground is not level, water seeps away etc. “3mm of rain” means for any given area, the amount of rain that fell (ie the volume) would fill that area to a height of 3mm.

For example, the Roman numeral MM is frequently used to designate that the units used in presenting information (financial and non-financial) in millions. For example, an annual salary of $60,000 might appear as $60k instead of $60M. The base unit for a millimeter is meter and the prefix is milli. The prefix milli is derived from the Latin mille meaning one thousand and is symbolized as m in the Metric System. Milli denotes a factor of one thousandth (1/1000th) which means that there are 1,000 millimeters in a meter.

All you have to do is count how many times it pivots to measure the rainfall. If you assume that rain is essentially pure water, then the weight is directly related to the volume. https://www.bookstime.com/ Divide that volume by the area of the top of the gauge and you get mm of rain. As you can imagine, it doesn’t matter how big this gauge is, as long as the sides are straight.