What Is 2/3 Cup Doubled? Easy Measurement Conversion Explained
The Quick Answer
2/3 cup doubled is 1 and 1/3 cups. That's 1 cup plus 1/3 cup. No magic here, just basic math that trips up a lot of home cooks.
If you're halving recipes or doubling them, understanding these fractions saves you from guessing games and botched dishes. Let's get into it.
Why This Measurement Comes Up Constantly
Recipes love to throw weird fractions at you. 2/3 cup is one of those measurements that sits in an awkward spot—too much for a half cup, not quite enough for a full cup.
You'll hit this number when:
- You're scaling a recipe up or down
- You're substituting ingredients and need to adjust ratios
- You're baking and precision actually matters
- You're cooking without the right measuring cup on hand
How to Measure 1 and 1/3 Cups
Here's where people get sloppy. Grab your measuring cups and pay attention:
Method 1: Full Cup + Third Cup
Fill a standard 1-cup measure completely. Then fill a 1/3 cup measure and add it. That's your 1 and 1/3 cups. Done.
Method 2: Two Thirds Times Two
If you only have 2/3 cup measures, fill it twice. Two 2/3 cup measurements equals 1 and 1/3 cups. This works, but it's messier.
Method 3: The Conversion Route
Convert everything to tablespoons or milliliters. 2/3 cup = about 10 tablespoons + 2 teaspoons. Double that and you get 20 tablespoons + 4 teaspoons, which converts back to 1 and 1/3 cups. Useful when you're working with tablespoon measurements only.
Quick Reference Table
| Original Amount | Doubled Amount | Simplified Form |
|---|---|---|
| 1/4 cup | 1/2 cup | 1/2 cup |
| 1/3 cup | 2/3 cup | 2/3 cup |
| 1/2 cup | 1 cup | 1 cup |
| 2/3 cup | 1 and 1/3 cups | 1 and 1/3 cups |
| 3/4 cup | 1 and 1/2 cups | 1 and 1/2 cups |
Common Mistakes That Ruin Your Recipe
Using a liquid measuring cup for dry ingredients. Don't. Dry measuring cups are designed differently. Fill them to the rim and level off.
Guessing on the 1/3 cup. Eyeballing a third of a cup is harder than it sounds. Those extra tablespoons add up, especially in baking where ratios matter.
Forgetting to convert other ingredients. When you double 2/3 cup of flour, you also need to double your other measurements. A recipe scaled wrong in one spot fails across the board.
Getting Started: Practical Application
Say a cookie recipe calls for 2/3 cup of butter and you want to double the batch. You need 1 and 1/3 cups of butter. Here's how to handle it:
- Fill a 1-cup measuring cup with butter
- Fill a 1/3-cup measure and add it to the 1 cup
- Done. That's your doubled amount
For liquids, use a clear measuring cup with markings on the side. Pour until you hit the 1 and 1/3 cup line. Check at eye level, not from above.
Conversions to Memorize
1 cup = 16 tablespoons = 48 teaspoons = 237 milliliters
2/3 cup = 10 tablespoons + 2 teaspoons = 158 milliliters
1 and 1/3 cups = 21 tablespoons + 1 teaspoon = 315 milliliters
Knowing these numbers means you can work with whatever measuring tools you have in your kitchen. No excuses for winging it.
When Precision Doesn't Matter (Much)
Cooking savory dishes gives you breathing room. If you're doubling 2/3 cup of onions for a soup, nobody's going to notice if you use 1 and 1/4 cups instead of 1 and 1/3 cups.
Baking is different. Flour ratios in bread and cake recipes are unforgiving. Get it right or get a dense, flat result.