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.
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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?
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.
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 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
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
|1 t||-||-||-||5 mL|
|3 t||1 T||-||1/2 fl oz||15 mL|
|-||2 T||1/8 c||1 fl oz||30 mL|
|-||4 T||1/4 c||2 fl oz||60 mL|
|-||5 1/3 T||1/3 c||2.7 fl oz||80 mL|
|-||8 T||1/2 c||4 fl oz||120 mL|
|-||12 T||3/4 c||6 fl oz||180 mL|
|-||16 T||1 c||8 fl oz||240 mL|
|-||-||2 c||16 fl oz||475 mL|
|-||-||3 c||24 fl oz||700 mL|
|-||-||4 c||32 fl oz||950 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
|1 cup||250 mL|
|1 pint||500 mL|
|1 quart||1 L|
|1 gallon||4 L|
Converting weight measurements
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
|1 oz||1/8 lb||28 g|
|4 oz||1/4 lb||113 g|
|8 oz||1/2 lb||227 g|
|12 oz||3/4 lb||340 g|
|16 oz||1 lb||454 g|
|32 oz||2 lbs||907 g|
Converting from cups to grams
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 cup||⅓ cup||½ cup||⅔ cup||¾ cup||1 cup|
|all-purpose flour||31 grams||42 grams||63 grams||83 grams||94 grams||125 grams|
|granulated sugar||50 grams||67 grams||100 grams||133 grams||150 grams||200 grams|
|brown sugar, packed||55 grams||73 grams||110 grams||147 grams||165 grams||220 grams|
|powdered sugar, unsifted||30 grams||40 grams||60 grams||80 grams||90 grams||120 grams|
|cornmeal||31 grams||41 grams||61 grams||81 grams||92 grams||122 grams|
|dry bread crumbs||27 grams||36 grams||54 grams||72 grams||81 grams||108 grams|
|butter||57 grams||76 grams||114 grams||151 grams||170 grams||227 grams|
|vegetable shortening||51 grams||68 grams||103 grams||137 grams||154 grams||205 grams|
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)
Converting the Yummly way
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.