How Many Tablespoons In Two Thirds Cup? | Kitchen Math

Two-thirds of a US cup equals 10 tablespoons plus 2 teaspoons, or roughly 10.67.

You’re halfway through a cookie recipe and the instructions call for two-thirds cup of brown sugar. Your set of dry measuring cups includes a 1/3, a 1/2, and a 1/4, but no 2/3. You do have a tablespoon measure, and a teaspoon. Suddenly a simple step feels like a math quiz.

The answer is straightforward: 10 tablespoons plus 2 teaspoons. That’s the standard US volume conversion, and it works for any ingredient — sugar, flour, butter, oil, or milk. This guide breaks down the math, gives you alternative measuring methods, and provides weight equivalents for common ingredients so you can keep right on cooking.

The Simple Math Behind 10 Tablespoons Plus 2 Teaspoons

The US customary system defines one cup as 16 tablespoons. To find a fraction of a cup, multiply 16 by the fraction. For two-thirds cup: 16 × 2/3 = 32/3 = 10.67 tablespoons.

Because a standard tablespoon is 3 teaspoons, the decimal part (.67 tablespoon) converts to 2 teaspoons (0.67 × 3 = 2.01). So the clean, fraction-friendly answer is 10 tablespoons plus 2 teaspoons.

If you prefer to think in nearby marks, two-thirds cup is 2 tablespoons and 2 teaspoons more than a half-cup (8 tablespoons), and 1 tablespoon and 1 teaspoon less than a three-fourths cup (12 tablespoons). These relationships make mental math easier when you’re scaling recipes on the fly.

Why This Conversion Trips Up Home Cooks

Most dry measuring cup sets include 1/4, 1/3, 1/2, and 1 cup. A 2/3 cup is often missing, so cooks resort to eyeballing or stacking smaller cups. The fractions themselves — thirds and sixteenths — don’t share a tidy mental shortcut, which is why the “10 T + 2 t” rule is worth memorizing.

• Using a 1/3 cup twice: The simplest hack. Fill a 1/3 cup measure two times and pour into your bowl. No math needed beyond recognizing that two-thirds is two one-thirds.
• Combining 1/2 cup, 2 tablespoons, and 2 teaspoons: If you don’t have a 1/3 cup, start with a 1/2 cup (8 tablespoons), then add 2 tablespoons (bringing you to 10 tablespoons), then add 2 teaspoons. That hits the exact volume.
• Using a liquid measuring cup: For liquids like oil or milk, a clear measuring cup with ounce and milliliter markings works perfectly. Two-thirds cup equals 5.33 fluid ounces or about 158 mL. Pour to that line.
• Weighing on a kitchen scale: For dry ingredients, weight is more reliable than volume, especially for flour. Two-thirds cup of all-purpose flour weighs about 83 grams; granulated sugar, about 133 grams. More weights are listed in the table below.
• Using a 1/4 cup plus adjustment: Two-thirds cup equals 2 and 2/3 of a 1/4 cup. That’s two full 1/4 cups plus two-thirds of a third 1/4 cup (which is about 2 tablespoons plus 2 teaspoons). It works but requires careful fractions.

Each method gets you to the same 10 tablespoons and 2 teaspoons. Pick the one that fits the tools you already have in your drawer.

Weight Equivalents for Common Ingredients

Volume measures like tablespoons and cups work the same for any ingredient — 10 tablespoons plus 2 teaspoons is always 2/3 cup. But weight varies by ingredient density. A kitchen scale eliminates guesswork, especially with flour, which compresses during scooping.

Per the 10 tablespoons plus 2 teaspoons conversion from the Exploratorium, the base volume is fixed. The table below gives approximate weights from cooking blog sources for the same volume of common ingredients.

Weights will vary slightly based on how you scoop and the brand of ingredient. For most home baking, these numbers are accurate enough to produce consistent results.

How to Measure Two-Thirds Cup Without a Dedicated 2/3 Cup

Most kitchens don’t own a 2/3-cup measure. Here are four reliable methods using tools you probably already have.

1. Use a 1/3 cup twice: Scoop and level a 1/3 cup, dump it into your bowl, then repeat. Total: two 1/3-cups equals 2/3 cup. This is the fastest method for dry ingredients.
2. Combine 1/2 cup plus 2 tablespoons plus 2 teaspoons: Start with a 1/2 cup (8 T), add 2 level tablespoons (10 T total), then add 2 level teaspoons. Works for both dry and liquid ingredients if you use a liquid measure for the wet ones.
3. Use a liquid measuring cup with ounce or milliliter markings: Look for the 5.33 fluid ounce or 158 mL line. Many glass measuring cups have these fractions printed alongside ounces. Pour slowly to the mark.
4. Weigh the ingredient: Set your scale to grams, place a bowl on it, tare, and add the ingredient until you reach the weight for your specific ingredient (see table above). This is the most precise method for dry goods like flour that settle differently in a cup.

Each method produces the same volume. The best choice depends on what you’re measuring and what tools are clean.

Fluid Ounces, Milliliters, and Why Precision Matters in Baking

Two-thirds cup equals exactly 5.33 US fluid ounces, as noted in the 5.33 fluid ounces guide from The Harvest Kitchen. That same volume is approximately 158 milliliters, close to the 160 mL mark on many metric measuring cups.

In baking, small measurement errors accumulate. A few extra teaspoons of flour can make cookies dense, while too little liquid can dry out a cake batter. That’s why memorizing the 10 tablespoons plus 2 teaspoons shortcut pays off — it removes guesswork when you’re in the middle of a recipe.

If you ever need to halve or double a recipe, keep this relationship in mind: 1/3 cup is 5 T + 1 tsp, so 2/3 cup is exactly double that.

The Bottom Line

Two-thirds cup always means 10 tablespoons plus 2 teaspoons by volume, regardless of what ingredient you’re measuring. For dry goods, weighing by grams (roughly 83 g for flour or 133 g for sugar) gives you even more consistent results. Memorize the shortcut, and you’ll never have to pause mid-recipe to do the math again.

If you’re working with a recipe that lists weights instead of cups, your kitchen scale and the approximate weights in this guide will get you where you need to go — no calculator required.