There are 5.26 tablespoons in a 1/3 cup of butter. The United States customary cup unit holds 8 ounces and 16 tablespoons. Since 1/3 of a whole account for 33 percent or .33 of it, .33 of 16 tablespoons is 5.26 tablespoons. This same formula applies to the British imperial system since an imperial cup also holds 16 imperial tablespoons.

**Differences Between US Customary and British Imperial System of Measurements**

When it comes to recipes, it is important to note that the U.S. customary cup holds 8 U.S. fluid ounces as opposed to 10 imperial ounces in the imperial cup. The fluid ounce measurements between U.S. customary and imperial systems are different, which means that tablespoon measurements will also be different. Below is a comparison of the tablespoon, ounce and cup measurements between U.S. customary and imperial system units in milliliters (mL):

- 1 U.S. tablespoon = 14.79 mL
- 1 United Kingdom tablespoon = 14.21 mL
- 1 U.S. fluid ounce = 29.573 mL
- 1 U.K. fluid ounce = 28.413 mL
- 1 U.S. cup = 235.59 mL
- 1 U.K. cup = 284.13 mL

One-third U.S. cup of butter that measures 5.26 U.S. tablespoons is 77.795 mL of butter. On the other hand, 5.26 imperial tablespoons or 1/3 imperial cup of butter is 74.74 mL. While the difference in measurements seems small, such small increments are sometimes enough to ruin a recipe.

**Is It in US Customary or Imperial System?**

Some recipes that you come across online often don't have any indication pf whether the portions that are called for in a recipe are in U.S. customary or imperial system units. One way of telling if a recipe is in U.S. customary or imperial systems is to look for cup or gill units.

Cups are very rarely used in recipes using imperial system units, while the gill is just as rare in recipes using U.S. customary units. Home cooks in the U.K. prefer to weigh their recipe portions rather than measure them in scoops. Recipes coming from U.K.-based recipe writers, therefore, will likely have measurements in dry weight units or metric system weight units.

**The Metric Cup**

Some recipes, although rare, may call for the metric system cup, which measures 250 mL. Since there are 16.67 metric tablespoons in 1 metric cup, 1/3 metric cup of butter is equivalent to 5.5 metric tablespoons of butter.

**Converting Between Systems of Measurement**

Understanding the differences between the systems of measurement is a good start towards knowing how to convert values into different measurement units. Having a handy app converter on your mobile device will make the task even easier. Kitchen tools such as a digital kitchen scale as well as measuring scoops for U.S. customary, imperial and metric systems will be helpful for those who don't want to bother with the conversion formulas.

**Converting Fractions to Decimals**

Some home cooks may not be comfortable with factions and prefer to have the recipe portions in decimals. Fractions are part of a whole and represent division.

A fraction has a top number called the numerator and a bottom number called the denominator. The top and bottom numbers in a fraction are separated by a division line called a vinculum. To get the decimal equivalent of a fraction, divide the numerator by the denominator, and the result is its decimal form. For example, 1/3 or 1÷3 = .33.