The kitchen reference
A measure of confidence.
Good kitchen math starts with saying what a number means. Here are the references, preparation choices and limits behind TwoGrams.
References reviewed . This is a deliberately small, curated reference set. Recipe-specific gram weights take priority. We do not copy recipes or reproduce entire third-party conversion tables.
A cup is a volume, not a weight.
The ingredient converter uses 236.5882365 mL for a US customary cup, 250 mL for a metric cup, and 240 mL for a US nutrition-label cup. A metric cup is not universal: historical imperial, Japanese and rice-cooker cups are not included.
US units follow NIST’s household weights and measures and SI conversion tables. The US food-labelling rule defines a 240 mL label cup. Metric kitchen conventions follow Health Canada. The Australian tablespoon is 20 mL.
| Standard | Tablespoon | Teaspoon |
|---|---|---|
| US customary | 14.7868 mL | 4.9289 mL |
| Metric | 15 mL | 5 mL |
| Australian | 20 mL | 5 mL |
A metric cup is 16⅔ metric tablespoons, not 16. Cup and spoon choices remain independent. An ounce of weight is exactly 28.349523125 g; a US fluid ounce is 29.5735295625 mL. We never substitute one for the other.
Our ingredient reference shelf.
These selected reference portions come from King Arthur Baking’s ingredient weight chart, except water. These are baking reference weights, not laboratory densities. Each ingredient has a specific preparation.
| Ingredient | Source portion | Reference weight |
|---|---|---|
| All-purpose flour Fluffed, sprinkled into a cup, then leveled; not sifted or packed. | 1 cup | ≈ 120 g |
| Bread flour Lightly filled and leveled. Brands and protein content vary. | 1 cup | ≈ 120 g |
| Whole wheat flour Lightly filled and leveled. | 1 cup | ≈ 113 g |
| Granulated sugar Level cup of granulated sugar; not powdered sugar. | 1 cup | ≈ 198 g |
| Brown sugar, packed Firmly packed. Unpacked brown sugar is not equivalent. | 1 cup | ≈ 213 g |
| Confectioners’ sugar, unsifted Unsifted; sifted sugar needs a different reference. | 1 cup | ≈ 113 g |
| Butter Solid butter, no air gaps. Whipped butter is not supported. | 0.5 cup | ≈ 113 g |
| Cocoa powder Level, lightly filled measure; not drinking chocolate. | 0.5 cup | ≈ 42 g |
| Rolled oats Rolled oats; not steel-cut, instant, or oat flour. | 1 cup | ≈ 89 g |
| Honey Reference weight varies with water content and temperature. | 1 tbsp | ≈ 21 g |
| Baking powder Level teaspoon. Use a scale capable of small quantities. | 1 tsp | ≈ 4 g |
| Table salt Table salt only; kosher and flaky salts differ substantially. | 1 tbsp | ≈ 18 g |
| Water Kitchen approximation of 1 g/mL, not an exact physical constant. | 1 ml | ≈ 1 g |
For calculations, TwoGrams treats the baking chart’s cups and spoons as US customary reference measures. A metric-cup estimate multiplies the source cup weight by 250 ÷ 236.5882365. This proportional model is our calculation, not a separately measured fact from King Arthur. No universal uncertainty percentage is claimed.
Fluff, sprinkle and level flour for the listed preparation. Sifting before measuring, scooping firmly or packing can change the weight. Our parser leaves those different preparations for review. Whole wheat refers to the chart’s Premium 100% whole wheat entry. Water uses the kitchen approximation 1 g/mL, supported by USGS; its actual density changes with temperature and dissolved substances.
1½ US cups of all-purpose flour × 120 g/cup ≈ 180 g. The same 1½ metric cups gives ≈ 190.2 g under the proportional model. One US cup of granulated sugar is ≈ 198 g, so flour and sugar cannot share one conversion factor.
Scale the quantity, then review the recipe.
Our recipe scaler multiplies ingredients by wanted servings ÷ original servings. Scaling 8 servings to 12 gives 1.5×. Two cups of flour becomes three cups, or approximately 360 g using the stated flour reference.
The parser accepts explicit units, leading decimals or fractions, and egg counts. Decimal commas are accepted, but comma values with three digits after the comma are flagged as ambiguous. Ranges, cans, packages, alternative quantities and prose stay on the card with review flags. Unknown ingredients with a known mass can be scaled; unknown volumes remain in their original units. Imported “oz” needs review unless explicitly written “oz wt”.
Fractions are calculated before rounding. For 3 eggs at half scale, keep 1½ eggs: beat an egg and weigh half its actual shell-free contents. Regional egg sizes differ, so the tool does not silently replace counts with a fixed gram weight. Tiny amounts keep sufficient digits, but a typical 1 g scale may not measure them reliably. No rounding is applied to intermediate calculations.
Different pan. Same intended batter depth.
The pan converter uses π × radius² for rounds and length × width for rectangles, measured inside. At the same batter depth, a 9-inch round needs 9² ÷ 8² = 1.265625 times the batter of an 8-inch round. With more than one pan, multiply area by pan count.
Changing intended batter depth adds target depth ÷ original depth to the ratio. Wall height is not batter depth. Tapered, tube and novelty pans need a different approach. See King Arthur’s pan substitution guide and inside pan measurement advice.
Keep the recipe’s temperature as a starting point and check for doneness. Batter depth, pan material and oven behaviour affect baking. Geometry alone cannot give a precise new cooking time.
Oven conversion is not fan adjustment.
Exact conversion: °F = °C × 9/5 + 32. Thus 180°C is 356°F. A 350°F dial setting is a practical rounding, not an exact equivalent.
The optional fan choices are named starting points: a 20°C reduction from AEG guidance, or a 25°F reduction discussed by King Arthur. They differ: 20°C of change equals 36°F. Check your model’s manual and avoid applying a reduction twice when your oven adjusts automatically.
Flour is always the 100% baseline.
Baker’s percentages divide each ingredient weight by all the flour in the dough. King Arthur’s professional reference explains the convention; its hydration guide includes preferment flour and water.
A 100 g starter at 100% hydration contributes 50 g flour and 50 g water. Added to 500 g flour and 350 g water, totals are 550 g flour and 400 g water: 72.73% hydration. Add 10 g salt and the dough weighs 960 g, with 1.82% salt. The starter is counted once in total dough mass.
For starter weight S and hydration H: starter flour = S ÷ (1 + H/100); starter water = S − starter flour. This first version accounts only for water and flour, not water contained in milk, eggs or butter.
Imperial is a different volume standard
The ingredient converter separately offers US liquid pints (473.176473 mL), Imperial pints (568.26125 mL), US fluid ounces (29.5735295625 mL) and Imperial fluid ounces (28.4130625 mL). Weight ounces remain 28.349523125 g. Imperial values derive from 4.54609 L per gallon, 8 pints and 160 fluid ounces; see Measurement Canada’s comparison. No location-based guess is made.
USDA food and nutrient references
The food reference tool contains 7,793 SR Legacy foods (final April 2018 release, published in FDC in 2019) and 469 Foundation Foods from the April 2026 download. These US data describe specific foods and preparation states; they are not a worldwide product catalogue. We retain 14,618 valid positive portion records with FDC and portion IDs. Source reference weights vary; they do not define universal density.
Nutrient amounts are per 100 g edible food. For a chosen weight W, multiply a reported nutrient by W ÷ 100. We show energy in kcal, protein/fat/carbohydrate/fibre/sugars in g and sodium in mg. Missing values stay unknown. Energy uses reported Energy (1008), otherwise Atwater specific (2048), otherwise Atwater general (2047), with the selected method shown. We do not calculate energy from incomplete macros. A source portion of A units weighing G grams scales to quantity Q × G ÷ A.
USDA downloads · Data documentation · CC0 licensing. Attribution: U.S. Department of Agriculture, Agricultural Research Service, FoodData Central. Retrieved 4 October 2026. The index loads only on the food tool; a small record group loads after selection. Search text stays in your browser.
Recipe and batch costing
Ingredient cost = scaled ingredient quantity in the pack unit ÷ pack quantity × pack price. For example, a 1 kg bag costing USD 4.00 and a scaled recipe using 300 g gives 300 ÷ 1,000 × 4 = USD 1.20. For 12 servings, that ingredient contributes USD 0.10 per serving. The pack price is entered by you; no live price or currency conversion is used.
Mass converts to mass and volume to volume without a density. Crossing volume and mass requires a supported ingredient and the stated preparation; otherwise the line stays unknown. Egg counts can be priced per egg. Resolve ambiguous ounces or unsupported recipe quantities first. The subtotal includes only priced lines; missing prices are never treated as zero. A zero price is allowed only when you explicitly enter it. Totals retain precision until currency display rounding.
The sheet reports ingredient costs, not a selling price or profit forecast. Labour, energy, packaging, delivery and other overheads are excluded unless included in an entered ingredient price. Save a reusable setup to preserve its recipe, pan comparison and cost entries locally.
Clear by design.
TwoGrams is an independent cooking tool, not affiliated with the reference publishers. The still-life photography was generated for TwoGrams. Recipe input is processed on your device; optional saving uses your browser’s storage. See privacy and local storage.