Don't fret if you find an interesting recipe with metric measurements. It's simple to convert grams to ounces or milliliters to cups. The metric system, known today as the International System of Units (SI), is the standard in most of the world. The United States is one of the few countries that uses the English, or customary, system. You can convert a metric recipe to English units using simple arithmetic.
Cooking by the Gram
Recipes tend to specify volumes, such as teaspoons, tablespoons and cups, rather than weights. Units of weight are more accurate, and can be the difference between success and failure when baking. But measures of volume work well in most recipes.
One gram equals 0.035 ounce. That's an ounce of weight, as opposed to a fluid ounce. Looking at it the other way, an ounce is equivalent to 28.6 grams. You can make a quick approximation by remembering that an ounce is about 30 grams.
Most electronic kitchen scales can convert from metric to English units at the touch of a button; see your scale's manual for instructions.
Common metric units of weight are grams and kilograms. Convert these to English units with simple multiplication.
Multiply grams by 0.035 for the equivalent weight in ounces. For example, 30 grams x 0.035 ounces/gram = 1.05 ounces.
Multiply grams by 0.0022 to obtain a measurement in pounds. If a recipe calls for 500 grams of an ingredient, then 500 grams x 0.0022 pounds/gram = 1.1 pounds.
A kilogram equals 1,000 grams. Multiply kilograms by 35.3 to obtain a weight in ounces. For example, 0.3 kilogram x 35 ounces/kilogram = 10.5 ounces.
Multiply kilograms by 2.2 if you want a weight in pounds. As an example, 1.2 kilograms x 2.2 pounds/kilogram = 2.64 pounds.
Convert metric volumes to English units through multiplication. English volume measurements in recipes include teaspoons, tablespoons, ounces, cups, pints, quarts and gallons. Metric volumes in recipes are usually expressed in liters or milliliters, and sometimes centiliters. A liter equals 100 centiliters, or 1,000 milliliters.
Multiply liters by 0.264 to convert to gallons, by 1.06 for quarts, by 4.23 for cups, by 33.8 for ounces, by 67.6 for tablespoons and by 202.9 for teaspoons. For example, 0.75 liter x 4.23 cups/liter = 3.17 cups.
Multiply centiliters by 0.003 to convert to gallons, by 0.011 for quarts, by 0.042 for cups, by 0.34 for ounces, by 0.068 for tablespoons and by 2.03 for teaspoons. For example, 50 centiliters x 0.042 cup/centiliter = 2.1 cups.
Multiply milliliters by 0.0003 to convert to gallons, by 0.001 for quarts, by 0.004 for cups, by 0.03 for ounces, by 0.007 for tablespoons and by 0.2 for teaspoons. As an example, 600 milliliters x 0.004 cups/milliliter = 2.4 cups.
Converting Celsius temperatures to Fahrenheit is slightly more complicated.
Multiply by 1.8, then add 32 degrees to the result.
For example, say a recipe tells you to preheat your oven to 175 degrees Celsius. Multiply 175 x 1.8 = 315. Then, add 32 degrees: 315 + 32 = 347 degrees Fahrenheit.