Converting one ingredient is easy. Converting a whole recipe has a handful of wrinkles that are worth knowing before you start, mostly around the things that should not be converted at all.
Work down the list, one ingredient at a time
Resist the urge to find one factor and apply it throughout. Every line needs its own density. Our recipe converter will take the whole list at once, but the principle is identical by hand: look up each ingredient separately.
Read the technique words as you go
Watch for packed, sifted, lightly spooned, firmly pressed, chopped, melted. They change the figure and are easy to skim past:
- "1 cup packed brown sugar" is 213 g. Without "packed" it would be nearer 145.
- "1 cup sifted flour" is 110 g. "1 cup flour, sifted" is 120 g.
- "1 cup chopped walnuts" is 117 g; "1 cup walnut halves" is 100 g.
Leave eggs alone
Eggs are sold by size and counted, not weighed. Two eggs is two eggs — do not convert it.
If you need precision, in a large batch or when halving a recipe calling for three, a US large egg is about 50 grams out of the shell: roughly 30 grams white and 18 grams yolk. Crack them into a bowl, whisk lightly, and weigh out what you need.
Keep small quantities in spoons
Do not convert half a teaspoon of vanilla or a quarter teaspoon of salt into grams. Measuring spoons are perfectly accurate at that scale and most domestic kitchen scales are not — many resolve only to 1 gram, which is useless for a 2 gram measurement of yeast.
Convert the bulk ingredients. Leave seasonings, extracts and leavening in spoons.
Liquids: convert or not, as you prefer
Water, milk and stock are close enough to 1 g per ml that converting them buys you little. Oil, honey, syrup and molasses are a different matter — honey is 340 g per cup against water's 237 — and weighing those is genuinely easier than scraping them out of a measuring cup.
Round sensibly, and round once
A conversion producing 118.7 grams of flour should be written as 120. Precision beyond the gram is false confidence given how much real-world densities vary. Do the rounding at the very end, after any scaling.
A worked example
Here is a standard cookie recipe converted line by line:
| Original | Converted | Note |
|---|---|---|
| 2 1/4 cups all-purpose flour | 270 g | 2.25 × 120 |
| 1 cup butter, softened | 227 g | 2 US sticks |
| 3/4 cup granulated sugar | 150 g | 0.75 × 200 |
| 3/4 cup packed brown sugar | 160 g | 0.75 × 213 |
| 2 cups chocolate chips | 340 g | 2 × 170 |
| 2 large eggs | 2 large eggs | Not converted |
| 1 tsp vanilla extract | 1 tsp | Too small to weigh |
| 1 tsp baking soda | 1 tsp | Too small to weigh |
| 1/2 tsp salt | 1/2 tsp | Too small to weigh |
Five lines converted, four deliberately left alone. That ratio is typical — most of a recipe's precision lives in a handful of bulk ingredients.
Ingredients that resist conversion entirely
Some lines simply should not become grams, and forcing them makes the recipe worse:
- "1 medium onion", "2 cloves garlic" — counted items where the recipe is tolerant by design.
- "A pinch of salt" — deliberately imprecise.
- "1 tin of chopped tomatoes" — a package size, and converting it just hides what to buy.
- "Oil for frying" — depends entirely on your pan.
- "Flour for dusting" — depends on your work surface.
A converted recipe that reads "1 medium onion (approximately 150 g)" is more awkward than the original, not less. Convert what benefits from precision and leave the rest in the language the cook actually thinks in.
Scaling at the same time
If you are also halving or doubling, convert first and scale second. Scaling round gram numbers is far easier than scaling awkward cup fractions, and you avoid compounding two roundings.
Remember that times and temperatures do not scale. A doubled cake needs a bigger tin and a longer bake, not twice the oven temperature. Our recipe scaler leaves any line mentioning minutes, hours or degrees untouched for exactly this reason.
Ranges, and "to taste"
Recipes are not always precise, and that is often deliberate. A line reading "2–3 tablespoons of milk, as needed" is telling you the right amount depends on your flour and your kitchen. Do not convert that into a fixed gram figure — you would be inventing a precision the author avoided on purpose.
Convert the lower end so you have a starting point, and keep the instruction to adjust. The same applies to "season to taste" and "enough flour to bring the dough together".
What to do with a recipe that mixes systems
Recipes that give some ingredients in grams and others in cups are common, particularly on sites that half-converted an original. Trust the grams — those are almost always the tested figures, with the cups added afterwards by a tool. If the two disagree for the same ingredient, that mismatch tells you the conversion was automated and not checked.
Keep the original the first time
Write your converted version alongside the original rather than replacing it. If the bake comes out oddly, you want to be able to tell whether the conversion was wrong or the recipe simply is not to your taste. After one successful run, the gram version is the one you keep — and it will be easier to follow than the original ever was.