TEAS conversions cheat sheet: metric prefixes, US units, and how to convert between them
Written and reviewed by Rebecca Moore, MSN, RN, CEN · 3 min read · Updated October 2026
Short answer
ATI's TEAS Math topics include converting within and between the standard (US customary) and metric systems. That means knowing the metric prefixes, the common US relationships such as 12 inches in a foot and 16 ounces in a pound, and a handful of bridges between the two, such as 2.54 centimetres in an inch and about 2.2 pounds in a kilogram.
Metric: one rule and four prefixes
Metric units scale by powers of ten, so converting within metric is moving a decimal point. Kilo means a thousand, centi means one hundredth, milli means one thousandth, and micro means one millionth. So 1 kilogram is 1,000 grams, 1 metre is 100 centimetres, 1 litre is 1,000 millilitres, and 1 milligram is 1,000 micrograms.
Going to a smaller unit gives a bigger number, and going to a larger unit gives a smaller one. Checking which way the number should move catches most decimal errors before you commit to an answer.
US customary units worth knowing by heart
Length: 12 inches in a foot, 3 feet in a yard, 5,280 feet in a mile. Weight: 16 ounces in a pound. Volume: 3 teaspoons in a tablespoon, 8 fluid ounces in a cup, 2 cups in a pint, 2 pints in a quart, and 4 quarts in a gallon.
These do not follow a pattern, which is why they cost points. Write the chain on your scratch paper at the start of the section if it helps, then convert one step at a time.
Bridging the two systems
NIST lists 1 inch as exactly 2.54 centimetres and 1 pound as about 0.45 kilograms, which is the same as about 2.2 pounds per kilogram. One fluid ounce is about 29.57 millilitres, often rounded to 30, a teaspoon is about 5 millilitres, and a tablespoon is about 15. To turn Fahrenheit into Celsius, subtract 32 and divide by 1.8; to go the other way, multiply by 1.8 and add 32.
The safest method is to multiply by a fraction equal to one, with the unit you want on top and the unit you are leaving underneath, so the old unit cancels. For 2 cups of fluid, 2 times 8 fluid ounces is 16 fluid ounces, and 16 times about 30 millilitres gives about 480 millilitres. If the answer choices are close together, check whether the question wants a rounded figure.
Conversions are quick points once they are automatic. Our free TEAS math practice questions mix them into word problems the way the real section does.
Common questions
Are conversions on the TEAS math section?
Yes. ATI lists converting within and between standard and metric systems as one of the measurement and data topics on TEAS Version 7.
Should I use 2.2 or 2.205 pounds per kilogram?
Use whatever the question gives you. If it gives nothing, 2.2 is the common rounded figure, and the answer choices usually tell you how precise you need to be.
Do I need to know Celsius and Fahrenheit for the TEAS?
Temperature is a standard conversion between the two systems, so it is worth knowing: subtract 32 and divide by 1.8 to get Celsius.