What's the difference? M, mm, ml, mil

Say hello to mil. No, this is not what your Great Aunt Mildred's bingo friends call her, but rather a prefix. You may think that mil would be short for "million." But, if you thought that, you'd be wrong. Mil actually means "thousand," and we can thank the Romans for that inconsistency.

M
The M is a Roman numeral for thousand. In Roman numeration, MMXVII actually means one thousand, one thousand, ten, five, one, one ... or 2017. Very often we associate "K" with thousand too. The K, however, stems from "kilo" which means thousand in the metric system. Just to keep things exciting "M" is also used to abbreviate million ... I know, this is very confusing, but "million" being abbreviated to "M" has less to do with historicity and more to do with laziness:

• MMXVII = 2017
• $129K = $129,000
• $1.75M = $1,750,000

mm
This is a linear unit of measurement within the metric system. Mill still means "thousandth" in this case and consequently a millimeter, is one thousandth of a meter. The whole milli thing isn't too hard to remember: millipede, millennium, millisecond, and so on. They all mean thousand.

ml
The "ml" stands for milliliter. The abbreviation "ml" is typically pronounced M-L, saying the letters out loud, or milliliter. This is a unit of measurement for liquids. Similar to mm, ml stands for one thousandth of a liter. Many labels for containers include an oz / ml conversion on the bottom. For instance you may see on the bottom of a shampoo bottle: 8 oz / 237 ml.

mil
Mil (pronounced "mill") is one thousandth of an inch. This form of measurement is often used to measure the thickness of flat objects like: plastic cards, credit cards, plastic zip lock bags, sheets of plastic tarp and so on. Most plastic ID cards like your driver's license and your credit cards are 30 mils. (Notice the plural form of mil). That means that your credit card is 30 mils ÷ 1,000 = 0.030 inches. Here at Container & Packaging Supply we have, for example, a 4 mil zip lock bag, and a 75 mil pail. This means that the zip lock bag is made of plastic 0.004 inches thick, and the pail is 0.075 inches thick.

Remembering that B9 and G46 are two very different spots on your BINGO card is critical to an uncontested win. Shouting "BINGO" prematurely is always a little embarrassing. Likewise, you wouldn't want to say a pail is 75 millimeters thick when it's actually 75 mils. There's a big difference between 75 millimeters and 75 mils ... like 2.875 inches! Can you imagine a pail being 3 inches thick?!