You're standing over a bowl of brownie batter and the recipe calls for exactly one-third of a cup of melted butter. You look at your drawer. The 1/3 measuring cup is missing. Gone. Maybe it’s in the dishwasher or buried in the "junk drawer" behind a rusted pizza cutter. You grab a tablespoon instead. Most people think this is a simple math problem, but honestly, it’s where most kitchen disasters start.
If you want the quick answer: 1/3 a cup in tablespoons is 5 tablespoons plus 1 teaspoon.
But here is the catch. Measuring 1/3 a cup in tablespoons isn't just about the number 5.33. It’s about the fact that American culinary measurements are kind of a mess. We rely on a system that doesn't divide cleanly by three. If you just heap five tablespoons into your bowl and call it a day, your cake is going to be dry. Your cookies will be crumbly. You've basically ignored that extra teaspoon that makes the ratio work.
The Math of 1/3 a Cup in Tablespoons
Let's look at the "Standard US Customary System." It’s a mouthful, right? Basically, it’s what we use in the States. One US cup equals 16 tablespoons.
Now, try to divide 16 by 3. You get 5.33333... and it just keeps going. You can't scoop "point-three" of a tablespoon unless you're a wizard. This is why we break it down into teaspoons. Since there are exactly 3 teaspoons in 1 tablespoon, that "0.33" of a tablespoon is exactly 1 teaspoon.
So, to get 1/3 a cup in tablespoons, you measure out five level tablespoons and then add one level teaspoon. Simple. But wait. Are you using a dry measuring cup or a liquid one? Most people think it doesn't matter. They’re wrong. Using a liquid measuring cup for flour—even if you get the "tablespoon" count right—can result in up to 20% more flour than the recipe intended because of how the powder packs down.
Why Accuracy Actually Matters (And When It Doesn't)
Cooking is an art; baking is a science. You've probably heard that a thousand times. If you're making a beef stew and you need 1/3 cup of red wine, does it matter if you're a teaspoon short? Not really. It’s fine. Splash it in. But if you’re making a souffle or a delicate sponge cake, that 1/3 a cup in tablespoons needs to be exact.
Think about the chemistry. Fat, like butter or oil, coats flour proteins. This prevents gluten from forming too quickly. If you under-measure that 1/3 cup by leaving out the final teaspoon, you have less fat. More gluten forms. Your "light and fluffy" cake suddenly has the texture of a bagel.
Standardization didn't really happen until Fannie Farmer published The Boston Cooking-School Cook Book in 1896. Before her, recipes called for "a walnut-sized lump of butter" or a "teacup of sugar." Imagine the chaos. We use tablespoons now because Fannie insisted on level measurements. If you’re using a spoon from your silverware drawer instead of a calibrated measuring spoon, you’re basically going back to the 1800s. Silverware spoons are shaped for your mouth, not for volume. They vary by as much as 50% in capacity.
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The Metric Ghost in the Machine
Most of the world looks at us like we’re crazy. They use grams. In the metric system, 1/3 of a cup is roughly 78.9 milliliters.
If you look at a professional kitchen, you won't see many people arguing about how many tablespoons are in a third of a cup. They have a digital scale. They know that a "cup" of water weighs 236 grams, so a third of that is 78.6 grams. It’s precise. No "heaping" or "scanting." Just numbers.
If you find yourself constantly converting 1/3 a cup in tablespoons, it might be time to buy a $15 kitchen scale. It’ll change your life. Seriously.
Common Mistakes When Converting 1/3 Cup
- The "Heaping" Habit. When people realize 1/3 doesn't fit perfectly into tablespoons, they often just do five "heaping" tablespoons. This is guesswork. A heaping tablespoon can hold nearly double the volume of a level one depending on the ingredient.
- The Liquid vs. Dry Spoon. While a tablespoon is technically a unit of volume, how you fill it changes everything. For 1/3 cup of flour, you should spoon the flour into the tablespoon and level it with a knife. Don't dip the spoon into the bag. Dipping packs the flour, giving you way more than you need.
- The 5-Tablespoon Trap. Many beginner cooks remember "5" but forget the "plus one teaspoon." That missing teaspoon is about 6% of the total volume. In a small recipe, that’s a huge margin of error.
Does the Country Change the Measurement?
This is the part that trips up people following recipes from UK or Australian blogs. Not all tablespoons are created equal.
In the United States, a tablespoon is approximately 14.8 ml. In the United Kingdom and Canada, a tablespoon is exactly 15 ml. It’s close enough that it rarely ruins a dish. But then there’s Australia. An Australian tablespoon is 20 ml.
If you are using an Australian recipe and it asks for 1/3 cup, and you try to convert 1/3 a cup in tablespoons using US spoons, you’re going to be way off. Always check the "origin" of your recipe. If the oven temps are in Celsius, your tablespoons are probably different too.
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Visualizing 1/3 Cup
Sometimes you don't even have a tablespoon. You’re camping. Or your kitchen is a disaster.
- 1/3 cup is roughly the size of a large lemon.
- It’s about the size of a golf ball and a half.
- If you’re looking at a standard 8oz stick of butter, 1/3 cup is exactly 5 and 1/3 tablespoons, which is marked clearly on the wrapper. Just cut a tiny bit past the 5-tablespoon mark.
Real World Application: The "Third" Rule
If you're doubling or tripling recipes, the math for 1/3 a cup in tablespoons gets even weirder.
- Double 1/3 cup: You need 2/3 cup. That’s 10 tablespoons plus 2 teaspoons.
- Triple 1/3 cup: This one is easy. It’s 1 full cup (16 tablespoons).
- Half of 1/3 cup: You need 1/6 cup. That’s 2 tablespoons plus 2 teaspoons.
Most people give up at 1/6 of a cup. They just eyeball it. But honestly, if you're making something like homemade mayonnaise or a light vinaigrette, the ratio of oil to emulsifier (like egg yolk or mustard) is the difference between a creamy sauce and a greasy puddle.
Expert Tip: The Displacement Method
If you're measuring something sticky like honey or peanut butter for your 1/3 cup, don't use tablespoons. It’s a nightmare. You’ll leave half the ingredient stuck to the spoons.
Instead, use a liquid measuring cup filled with water to the 1-cup mark. Add your peanut butter until the water rises to 1 and 1/3 cups. Pour the water off. You now have exactly 1/3 cup of peanut butter with zero mess and no need to count out five annoying tablespoons.
Actionable Steps for Perfect Measurements
To stop guessing and start cooking better, implement these three habits today.
First, standardize your tools. Toss the mismatched plastic spoons you got at the dollar store and get a heavy-duty stainless steel set. Look for a set that actually includes a 1/3 cup and even a 1/8 cup. It saves so much mental energy.
Second, memorize the 5+1 rule. 1/3 cup = 5 tablespoons + 1 teaspoon. Say it out loud. Tape it to the inside of your pantry door. It’s the most common conversion you'll need, especially for butter and oil.
Third, level every single scoop. Use the back of a butter knife. No mounds, no "looks about right." Leveling ensures that your 1/3 a cup in tablespoons is actually the volume the recipe developer intended.
The nuances of volume measurement might seem trivial, but they are the literal foundation of culinary consistency. Whether you are whisking a roux or folding a batter, knowing these tiny shifts in math ensures that the dish you make today is just as good as the one you make next year. Stop eyeing the spoon and start leveling it off. Your sourdough (and your family) will thank you.