How to Convert Metric Units to US Customary Units

How to Convert Metric Units to US Customary Units: A Guide for the Mathematically Challenged

The world is your oyster! Cook international recipes with ease using this guide to cooking conversions.

Let’s get this out of the way right up front — I’m no math whiz, and I suspect that’s one of the reasons I’m a fairly reluctant baker. There are a lot of numbers in those recipes that don’t always compute for me. How many cups in a liter? How many grams in a teaspoon? And then they’re always telling you to get a digital scale, eesh. (Spoiler alert: You should.)

For bakers — or cooks who like British recipes — you need to be able to do a few quick cooking conversions. Use the charts below to slide easily from the U.S. customary system (cups, pints, pounds) that we grew up with here in the United States and the metric system (grams, milliliters) that the rest of the world seems to use.

One important note: Yummly has a built-in converter! On any recipe, just to the right of the "Ingredients (Shop Ingredients)" line, you'll see text that says "US | METRIC". Click on that, and watch the math get done for you. You can even save your overall preference in your personal profile settings (more on that below).

Not using a Yummly recipe? Read on:

Measuring basics: When is a cup not a cup?

Measuring spoons

Before we get started, let's talk quickly about weight vs. volume and liquid ingredients vs. dry ingredients. Weight and volume are two different methods of measuring: the first focused on how heavy something is and the second on how much space it takes up. Weight measures include pounds, ounces, kilograms, and grams. Volume measures include teaspoons, tablespoons, fluid ounces, cups, pints, quarts, liters, and milliliters.

The difference between weight and volume measurements lies at the heart of most confusion when converting from metric to U.S. customary measurements: While liquids are generally measured by volume across the board, American recipes tend to measure dry ingredients by volume, whereas metric recipes tend to measure them by weight.

Liquid ingredients

Liquids are typically measured by volume because there's not a big variance in the weight between different types of liquids. This makes it fairly straightforward to convert between different measurement systems as you're just switching from one unit of volume to a different one.

One key to remember here, though: a fluid ounce (fl oz) is not the same thing as an ounce! Why not? This will become clearer when we look at dry ingredients, but in short, a fluid ounce is a volume measurement (used only for liquids) and an ounce is a weight measurement. That being said, 1 cup will always equal 8 fluid ounces.

Dry ingredients

Dry ingredients are a bit more complicated. While a cup equals 8 fluid ounces, there's no standard for how much a cup of dry ingredients weighs. Case in point: A cup of feathers and a cup of lead marbles definitely do NOT weigh the same. A cup of tightly packed brown sugar will weigh more than a cup of brown sugar that's been loosely scooped into the measuring cup. (See converting from cups to grams below for specific cooking examples). This is the main reason why professional bakers prefer using weight measurements: You can get more consistent results when measuring dry ingredients by weight as opposed to volume (which leaves more room for fluctuation).

Liquid volume conversions

Liquid measuring cup

The first lesson in conversion is to remember that liquid and dry ingredients are measured differently. Liquids are measured by volume: teaspoons, tablespoons, fluid ounces, cups, pints, and quarts are the U.S. customary units, whereas milliliters (mL) and liters (L) are metric units of measurement. Before we get into converting from U.S. to metric, let's take a closer look at the different units used in the U.S.:

U.S. Customary Measurement Equivalents

  • 1 tablespoon = 3 teaspoons
  • 1 cup = 16 tablespoons
  • 1 pint = 2 cups
  • 1 quart = 2 pints
  • 1 gallon = 4 quarts

Armed with that information, this chart will help you convert from a variety of typical U.S. volume measurements to the metric equivalent in milliliters:

Liquid Ingredient Conversion Chart

TeaspoonTablespoonCupFluid OuncesMilliliters
1 t---5 mL
3 t1 T-1/2 fl oz15 mL
-2 T1/8 c1 fl oz30 mL
-4 T1/4 c2 fl oz60 mL
-5 1/3 T1/3 c2.7 fl oz80 mL
-8 T1/2 c4 fl oz120 mL
-12 T3/4 c6 fl oz180 mL
-16 T1 c8 fl oz240 mL
--2 c16 fl oz475 mL
--3 c24 fl oz700 mL
--4 c32 fl oz950 mL

If your recipe doesn't require a ton of precision (looking at you, soups and stews), using these wavy-handed equivalents is a totally acceptable option:

Liquid Conversion Estimates

ImperialMetric
1 cup250 mL
1 pint500 mL
1 quart1 L
1 gallon4 L

Converting weight measurements

Kitchen Scale

Weight conversions are fairly straightforward if you can remember that there are 16 ounces in a pound and 1 ounce weighs 28 grams.

Here are some common weights to put to memory (or on your fridge).

Weight Conversion Chart

OuncesPoundsGrams
1 oz1/8 lb28 g
4 oz1/4 lb113 g
8 oz1/2 lb227 g
12 oz3/4 lb340 g
16 oz1 lb454 g
32 oz2 lbs907 g

Converting from cups to grams

Measuring Cups

Converting cups or tablespoons to grams is troublesome business since you're converting from volume to weight. This means there's no set formula — the conversion will vary from food to food. Conversions, you’ll find, are not nice and neat. They involve a bit of rounding. The easiest way to go about it is to use a metric scale, of course. Short of that, keep these common conversions handy (especially if you’re a baker):

  • One cup of all-purpose flour weighs 4 3/8 ounces or 125 grams
  • One cup of granulated sugar weighs 7 ounces or 200 grams
  • One cup packed brown sugar weighs 7 3/4 ounces or 220 grams
  • One cup unsifted powdered sugar weighs 4 1/4 ounces or 120 grams
  • One cup yellow cornmeal weighs 4 1/4 ounces or 122 grams
  • One-half cup butter (8 tablespoons or one stick) weighs 4 ounces or 114 grams
  • One-quarter cup dry bread crumbs weighs 1 ounce or 27 grams
  • One-quarter cup solid vegetable shortening weighs 1 ¾ ounces or 51 grams

Cups To Grams Conversion Chart

-¼ cup⅓ cup½ cup⅔ cup¾ cup1 cup
all-purpose flour31 grams42 grams63 grams83 grams94 grams125 grams
granulated sugar50 grams67 grams100 grams133 grams150 grams200 grams
brown sugar, packed55 grams73 grams110 grams147 grams165 grams220 grams
powdered sugar, unsifted30 grams40 grams60 grams80 grams90 grams120 grams
cornmeal31 grams41 grams61 grams81 grams92 grams122 grams
dry bread crumbs27 grams36 grams54 grams72 grams81 grams108 grams
butter57 grams76 grams114 grams151 grams170 grams227 grams
vegetable shortening51 grams68 grams103 grams137 grams154 grams205 grams

Temperature conversions

You can bake in Celsius? Well, yes you can — and much of the world does. To cope, let’s bring it back to middle school, shall we? The official formula to switch from Celsius to Fahrenheit is this:

(°C*9)/5 + 32 = °F

Multiply the degrees Celsius by 9, divide by 5, then add 32 to get the equivalent degrees Fahrenheit.

If you need to go the other way, it’s this:

[(°F-32)*5]/9 = °C

Subtract 32 from the degrees Fahrenheit, multiply by 5, then divide by 9 to get the equivalent degrees Celsius.

If the math makes you crazy, then post these common oven temperatures prominently instead!

Temperature Conversion Chart (rounded to the nearest 5° increment)

FahrenheitCelsius
250°F120°C
300°F150°C
325°F160°C
350°F175°C
400°F205°C
425°F220°C

Converting the Yummly way

Mixed measuring tools

If you’re reading this, lucky you: Yummly does all these pesky conversions for you. You can set your preferred measurements — whether they be U.S. or Metric — in your account settings. Once you save your setting, every recipe on Yummly will appear in your preferred unit of measurement.

If you prefer to choose on a recipe-by-recipe basis, you can toggle between U.S. and Metric for an individual recipe as well. Go straight to the Ingredients list on any recipe and you’ll see where to change it, top right.

When all else fails, ask Alexa

Thanks to the powers that be (i.e. Google, Amazon, and Apple), smart home technology is now there to do the math for you — and all you have to do is think out loud, starting with “Hey Siri,” “Hey Alexa,” or “OK Google.”

Conversions, in fact, are one of the things that most smart home devices get right.

Cooks Illustrated did a comparison and they did great with questions and tasks like:

  • How many grams are in 6 ounces?
  • Convert 20 grams to ounces
  • How many tablespoons are in ¼ cup?
  • Convert 350 degrees Fahrenheit to Celsius
  • Convert 190 degrees Celsius to Fahrenheit
  • What’s one-half of ¾ cup?
  • What is ⅔ ounces in grams?

And that’s because, at the root, it’s all just a lot of math.

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