Baking Conversion Calculator Guide: Cups, Grams & Ounces (2026)

Why Weight Beats Volume in Baking

Volume measurements like cups and tablespoons tell you how much space an ingredient takes up, not how much of it you actually have. That's fine for water, which is always the same density. It's a problem for almost everything else in your pantry.

Flour is the classic example. Freshly sifted flour is airy and light. Flour that has settled in a bag for two weeks is dense and packed. When you scoop a cup, the amount you get depends on how the flour was stored, whether you sifted it, and your scooping technique. America's Test Kitchen documented home bakers measuring anywhere from 113g to 170gper cup of all-purpose flour — a 50% swing using the exact same measuring cup.

Professional bakers use grams because a kitchen scale gives you the same number every time. 120g is 120g whether the flour is sifted or packed, humid or dry. This is why pastry recipes from serious sources always include weight measurements alongside (or instead of) volume.

Serious Eats conducted a controlled test showing that cookies made with 170g of flour (over-packed cup) spread significantly less and were noticeably denser than the same recipe made with 120g — despite both bakers measuring "1 cup." The fix costs nothing: use a kitchen scale or use the spoon-and-level method (spoon flour into the cup, then sweep excess off with a straight edge).

Common Baking Ingredients: Cups to Grams

The values below follow King Arthur Baking and USDA FoodData Central measurements. All-purpose flour is the most variable; butter and sugar are more consistent between techniques.

Notice how honey (340g/cup) is nearly three times heavier than cake flour (100g/cup) by volume. This is why you cannot swap ingredients by volume alone — density matters enormously.

US Cups vs Metric: Full Conversion Table

1 US legal cup = 240 ml exactly (used on US nutrition labels). 1 US customary cup = 236.6 ml (used in most American recipes). The difference is small enough to ignore for home baking. For the table below, 240 ml is used.

When scaling a recipe, use our baking conversion calculator to avoid manual arithmetic errors, especially for fractional measurements like 2/3 cup or 3/4 cup.

Oven Temperature Conversions

Most American recipes use Fahrenheit; most European and Australian recipes use Celsius. Gas mark is common in older UK recipes. The formula: °C = (°F − 32) × 5/9. Here are the most common baking temperatures:

Important: oven calibration varies. According to Cook's Illustrated, home ovens can run 25°F off from the dial setting. An inexpensive oven thermometer (under $15) eliminates this guesswork and is one of the highest-value kitchen tools you can own.

Pan Size Substitutions

Pan size affects bake time and texture. A shallower pan means a thinner layer of batter that bakes faster; a deeper pan means slower, more even cooking. The key metric is volume — if you keep the volume the same and adjust bake time, substitutions work well.

When substituting pans, reduce bake time by about 25% if moving to a wider, shallower pan (batter will be thinner). Increase bake time by 10–15% if moving to a deeper, narrower pan. Start checking with a toothpick 5 minutes before the adjusted time.

Top 5 Baking Measurement Mistakes

These are the most common errors that cause recipes to fail, ranked by how often they come up in recipe troubleshooting forums and test kitchen analyses.

1. Packing flour into the measuring cup. Scooping the cup directly into the flour bag packs it, adding up to 50% more flour than intended. Always spoon flour into the cup and level it off. Or better yet, use a scale.
2. Using volume measures when the recipe calls for weight.If a recipe says “200g of sugar,” don't convert it to “about 1 cup” and eyeball it. Use a scale. The conversion exists, but it introduces error.
3. Using the wrong pan size without adjusting bake time.Using an 8" pan when a recipe calls for 9" means thicker batter and a longer bake. The outside can look done while the center is still raw. Always adjust time and test with a toothpick.
4. Not leveling liquid measurements correctly. When measuring liquid in a cup measure, set it on a flat surface and read at eye level. Looking down at the cup from above introduces parallax error and makes volumes look higher than they are.
5. Confusing teaspoons (tsp) and tablespoons (tbsp).A tablespoon is 3 teaspoons. Using 1 tbsp of baking soda instead of 1 tsp triples the leavener — enough to make a cake taste metallic and collapse. The abbreviations look similar; double-check.

According to a survey by King Arthur Baking's Baker's Hotline, flour measurement errors account for the majority of calls about dense cakes and flat cookies. Weight measurement eliminates all five of these problems.

Frequently Asked Questions

How many grams is 1 cup of flour?

1 cup of all-purpose flour weighs approximately 120–130 grams depending on how you measure. King Arthur Baking specifies 120g for spooned-and-leveled, while scooping directly from the bag can pack flour to 150g or more — a 25% difference that significantly affects results. Cake flour is lighter at about 100g per cup; whole wheat flour is denser at about 130g.

How many ml is 1 cup?

1 US cup equals exactly 236.6 ml, commonly rounded to 240 ml. A UK or Australian cup is 250 ml. So if you're using a recipe from a different country, check which cup standard it uses before converting. For most home baking, the 4 ml difference between 236.6 and 240 is negligible.

What is 350°F in Celsius?

350°F converts to 177°C, commonly rounded to 180°C in recipes. This is the single most common baking temperature, used for everything from chocolate chip cookies to birthday cakes. The conversion formula is: °C = (°F − 32) × 5/9.

Can I substitute a 9×13 pan with two 8-inch round pans?

Yes, with a small adjustment. A 9×13 pan holds about 14 cups of batter; two 8-inch rounds hold about 12 cups combined. Fill each round pan no more than two-thirds full and reduce bake time by about 5 minutes since the batter layer is thinner. This substitution works well for most layer cake recipes.

Why do professional bakers use grams instead of cups?

Grams measure mass, which is always consistent. A cup of flour can vary by up to 50% based on how it's measured — America's Test Kitchen documented readings from 113g to 170g using identical cups. Professional bakers use scales because the same recipe produces the same result every time, regardless of the baker, the humidity, or how long the flour has been sitting.

How many tablespoons are in 1/4 cup?

1/4 cup = 4 tablespoons = 12 teaspoons. The full hierarchy: 1 cup = 16 tablespoons = 48 teaspoons. So 1/3 cup = 5 tablespoons + 1 teaspoon, and 3/4 cup = 12 tablespoons. These conversions matter when scaling recipes down — halving 1/3 cup is 2 tablespoons + 2 teaspoons, not a clean fraction.