Cooking measurements look simple until you're translating a French pastry recipe in grams into a U.S. kitchen with cups and tablespoons, or scaling a small recipe up for a dinner party. Volume-to-volume conversions are easy. Volume-to-weight is where most kitchen disasters originate, because flour, sugar, and other dry ingredients don't behave the same way at the same volume.
Key Takeaways
- Volume-to-volume conversions are exact: 1 tbsp = 3 tsp = 15 mL (US standard).
- Volume-to-weight conversions are ingredient-dependent: 1 cup of flour ≠ 1 cup of sugar by weight.
- Baking benefits hugely from weight-based measurement; cooking tolerates volume-based.
- Oven temperatures: °F = °C × 9/5 + 32; common reference points worth memorizing.
- US and UK measurements differ for cup, pint, and gallon, so recipe origin matters.
Volume Equivalents (US Standard)
These conversions are exact within the US measurement system:
| Unit | Equivalent |
|---|---|
| 1 tablespoon (tbsp) | 3 teaspoons (tsp) |
| 1 fluid ounce | 2 tbsp |
| 1/4 cup | 4 tbsp = 60 mL |
| 1/3 cup | 5 tbsp + 1 tsp ≈ 80 mL |
| 1/2 cup | 8 tbsp = 120 mL |
| 1 cup | 16 tbsp = 240 mL (approx, US legal cup is 240 mL; US customary 236.6 mL) |
| 1 pint | 2 cups = 473 mL |
| 1 quart | 4 cups = 946 mL |
| 1 gallon | 16 cups = 3.785 L |
Common Volume Conversions: US ↔ Metric
| US Volume | Metric (mL) |
|---|---|
| 1 tsp | 5 mL |
| 1 tbsp | 15 mL |
| 1 fl oz | 30 mL |
| 1/4 cup | 60 mL |
| 1/2 cup | 120 mL |
| 1 cup | 240 mL |
| 2 cups (pint) | 475 mL |
| 1 quart | 950 mL |
| 1 gallon | 3.8 L |
These are working values rounded to clean numbers. Most cooking tolerates a 1–2% error.
Dry Ingredient Weights
Volume-to-weight for dry ingredients varies by density and how it's measured (sifted vs spooned vs packed). Approximate values for common ingredients per US cup:
| Ingredient | Grams per cup |
|---|---|
| All-purpose flour | 120 g |
| Bread flour | 130 g |
| Cake flour | 115 g |
| Whole wheat flour | 130 g |
| Granulated sugar | 200 g |
| Brown sugar (packed) | 220 g |
| Powdered sugar | 120 g |
| Cocoa powder | 100 g |
| Butter | 227 g (1 cup = 2 sticks) |
| Cornstarch | 130 g |
| Rolled oats | 90 g |
| Rice (uncooked) | 200 g |
| Honey | 340 g |
These vary by source. For baking, working in grams with a kitchen scale is dramatically more reliable than using cup measurements.
Liquid Weights
For most cooking purposes, water and similar low-viscosity liquids weigh about 1 g per mL:
- 1 cup water = 240 mL = 240 g
- 1 tbsp water = 15 mL = 15 g
Denser liquids differ:
- 1 cup honey ≈ 340 g (density 1.42 g/mL)
- 1 cup maple syrup ≈ 320 g
- 1 cup vegetable oil ≈ 220 g
- 1 cup milk ≈ 245 g
Oven Temperature Conversions
°C → °F: multiply by 9/5, add 32 °F → °C: subtract 32, multiply by 5/9
Common cooking temperatures:
| °F | °C | Description |
|---|---|---|
| 250 | 120 | Very low; slow roasting |
| 300 | 150 | Low; slow cooking |
| 325 | 160 | Moderate-low; cakes |
| 350 | 175 | Moderate; most baking |
| 375 | 190 | Moderate-high |
| 400 | 200 | High; roasting |
| 425 | 220 | Very high; pizza, bread |
| 450 | 230 | Very high; pre-heating |
| 475 | 245 | Extremely hot |
Gas oven marks (UK / Europe) map roughly to:
- Gas Mark 1 ≈ 275°F (140°C)
- Gas Mark 4 ≈ 350°F (175°C)
- Gas Mark 7 ≈ 425°F (220°C)
- Gas Mark 9 ≈ 475°F (245°C)
Why Baking Wants Weight
Volume measurements of flour can vary by 30% depending on how the flour was scooped, settled, and sifted. A "scooped" cup is much denser than a "spooned and leveled" cup. For most cooking this barely matters; for baking it can be the difference between a tender cake and a dense, dry one.
A digital kitchen scale running in grams eliminates this entire category of error. Once you've tried a recipe in grams, going back to cups feels imprecise.
If you must use cups for flour:
- Stir the flour to loosen it
- Spoon it into the cup
- Level off with a flat edge
Never scoop directly with the cup unless the recipe says so.
Scaling Recipes Up or Down
To scale a recipe, multiply every quantity by the same scale factor:
Scale factor = (desired servings) / (original servings)
A recipe for 4 needs to feed 6: scale factor = 1.5. Every ingredient gets multiplied by 1.5.
Two caveats:
- Cooking time doesn't scale linearly. Doubling a recipe doesn't double the cooking time. A bigger casserole takes longer than a small one, but not 2x.
- Spices and seasonings often need less than linear. Doubling cayenne can make a dish painfully hot. Spice up by 1.5–1.7x when doubling, taste, and adjust.
Worked Example: Converting a French Recipe
A French chocolate cake recipe:
- 200 g chocolate
- 150 g butter
- 4 eggs
- 100 g sugar
- 60 g flour
Bake at 180°C for 25 minutes.
For a U.S. cook without a scale:
- 200 g chocolate ≈ 7 oz
- 150 g butter ≈ 2/3 cup (or 10.5 tbsp; better as weight)
- 4 eggs ≈ unchanged (eggs are weights, ~50–55 g large)
- 100 g sugar = 1/2 cup
- 60 g flour = 1/2 cup
- 180°C = 350°F
A scale would make this whole conversion unnecessary. The 60 g of flour as a US cup measurement is only approximate. The actual cup of flour measured by spooning is closer to 120 g, meaning "1/2 cup" rounds slightly low for 60 g. Weighing eliminates the issue entirely.
Common Mistakes
Confusing US and UK cups. A US cup is 240 mL; a UK cup (when used) is 250 mL. A US tablespoon is 15 mL; an Australian tablespoon is 20 mL.
Scooping flour with the cup. This packs the flour and overweights it. Spoon and level.
Treating "ounce" as one unit. Fluid ounce is volume; ounce by weight is mass. They are different.
Doubling spice and salt linearly. Diminishing returns; under-scale heat and aromatics, taste, adjust.
Ignoring temperature differences in convection vs conventional ovens. Convection ovens typically cook faster, so reduce temperature by 25°F (15°C) or time by 25%.
Substituting baking powder and baking soda 1:1. They are not interchangeable. Baking soda is roughly 3–4x as powerful as baking powder.
Practical Scenarios
Scenario 1: International baker. A recipe lists "1 stick of butter." A stick of US butter = 1/2 cup = 113 g = 8 tbsp. For European baking: 113 g.
Scenario 2: Halving a recipe. A recipe for 8 servings: scale factor 0.5. Every ingredient halved. Cook time stays similar; reduce only marginally.
Scenario 3: Substituting weight for volume. A bread recipe calls for "3 cups flour." Spooned and leveled: ~360 g. With a scale: weigh out 360 g for reproducibility.
Scenario 4: Temperature mismatch. A recipe says 220°C. Set US oven to 425°F (close enough; exact is 428°F).
FAQ
Why does my baked recipe come out differently each time? Most often: imprecise flour measurement. Weighing eliminates the inconsistency. Other sources include oven temperature variance and altitude.
Is a US cup the same as a UK cup? Not exactly. US cup = 240 mL; the UK doesn't use cup measurements as much, but when it does, a metric cup is 250 mL. The difference is small in volume but can matter in baking.
How many tablespoons in a cup? 16 US tablespoons in 1 US cup.
Can I use a kitchen scale for liquids too? Yes. Water is 1 g per mL, so 100 g of water = 100 mL. Denser liquids weigh more per mL.
Why are baking recipes more sensitive to measurement than cooking? Baking is chemistry: leavening, gluten development, and ratios of fat to flour to sugar matter precisely. Cooking is more forgiving.
How do I scale a recipe to a different number of servings? Multiply every ingredient by (desired servings ÷ original servings). Adjust cooking time and seasonings less than linearly.
What's the difference between a stick of butter and a cup? 1 stick = 1/2 cup = 8 tablespoons = 4 ounces = 113 grams. Two sticks make one cup.
Related Tools
The Cooking Converter handles common kitchen unit conversions in both directions. For general units, the Volume Converter, Weight Converter, and Temperature Converter cover everything.
Related Articles
Final Thoughts
A digital kitchen scale is one of the highest-leverage investments a home cook can make. Volume measurements are an inheritance from a time before scales were cheap. For cooking, they remain perfectly serviceable; a "splash" of olive oil or a "handful" of herbs is part of the craft. For baking, where a 10% deviation in flour can ruin a recipe, weight measurements are the upgrade. The conversions in this article are useful for translating between systems; the scale eliminates the need to convert at all.