Cooking Measurement Converter, Explained

After reading this you will be able to convert any recipe amount between cups, spoons, millilitres, grams and ounces, and you will know why a cup of flour and a cup of honey weigh completely different amounts.

A recipe says 2 cups of flour. Your scale reads grams. A cup is a volume, a gram is a mass, and the bridge between them is density: how much mass fits in a given volume. All-purpose flour packs about 120 grams into a cup. Honey packs about 340 grams into that same cup. So the same "1 cup" instruction can mean anything from a light dusting to a heavy pour, depending on what you are measuring.

This tool converts between six units (cups, tablespoons, teaspoons, millilitres, grams and ounces) using the density of the specific ingredient you pick. That last part matters. A generic converter that treats a cup as "236.6 mL of water" will be wrong by a factor of nearly three when you hand it honey.

What the tool does and one example to anchor it

Volume units (cups, tablespoons, teaspoons, millilitres) all describe the space something takes up. Weight units (grams, ounces) describe mass. Converting inside one group is pure arithmetic with fixed factors. Converting across the groups needs a density.

Take flour. Its cooking density is about 120 g per cup, and a US cup is 236.6 mL. So flour holds roughly 120 / 236.6 \approx 0.507 grams per millilitre. Compare that to a few others:

Typical cooking densities used by the converter
Ingredient	Grams per cup	Grams per mL
Water	237	1.000
Flour (all-purpose)	120	0.507
Sugar (granulated)	200	0.845
Brown sugar (packed)	220	0.930
Butter	227	0.959
Honey	340	1.437

Water is the reference point at almost exactly 1 gram per millilitre. Flour is about half that. Honey is denser than water because sugar dissolved in it packs more mass into the same space.

When to use weight and when volume is fine

Use weight whenever precision changes the result. Baking is the clear case. Bread, cakes and pastry depend on ratios of flour to water to fat, and a 20% error in flour will change the dough. Weighing removes the guesswork that comes from how tightly you scoop.

Volume is fine for forgiving jobs: a splash of oil in a pan, a cup of stock in a soup, most stovetop cooking where a little more or less does not break anything. Liquids are also easy to measure by volume because they always fill a cup the same way. It is the dry, compressible ingredients (flour, powdered sugar, cocoa) where volume betrays you.

If a recipe gives both weight and volume, trust the weight. Serious baking recipes list grams first for exactly this reason.

The formula and why it works

Every conversion goes through volume in millilitres as a common currency. First convert the input unit to millilitres or grams, then out to the target unit. The one piece that carries the ingredient is density.

m = V \cdot \rho

Here m is mass in grams, V is volume in millilitres, and \rho (rho) is density in grams per millilitre. To go the other way, divide:

V = \dfrac{m}{\rho}

The volume units themselves are fixed by the US customary system. One cup is 236.6 mL, split into 16 tablespoons and 48 teaspoons. So one tablespoon is 236.6 / 16 \approx 14.79 mL and one teaspoon is 236.6 / 48 \approx 4.929 mL. Weight units are fixed too: one ounce is 28.35 g.

Put together, a cups-to-grams conversion is just:

m = n_{\text{cup}} \cdot 236.6 \cdot \rho

where n_{\text{cup}} is the number of cups. Everything else is chaining these steps.

Worked example: 2 cups of flour

Reproducing the demo (flour, 2 cups)

The demo button loads the defaults: ingredient flour, amount 2, unit cups. Follow the arithmetic.

Convert cups to millilitres: 2 \times 236.6 = 473.2 mL.
Apply flour density \rho = 0.507 g/mL: 473.2 \times 0.507 \approx 240 g. This matches the 120 g/cup figure directly (2 \times 120 = 240).
Convert grams to ounces: 240 / 28.35 \approx 8.47 oz.
Convert to spoons if you have no cup: 473.2 / 14.79 \approx 32 tablespoons.

So 2 cups of flour is about 240 grams, 8.47 ounces, or 32 tablespoons. Swap the ingredient to honey and the same 2 cups jumps to 2 \times 340 = 680 grams.

The chart below shows how the same "1 cup" translates to very different weights across ingredients.

One cup ranges from about 90 g of oats to 340 g of honey, a spread of nearly four to one.

See how density changes the answer

The single idea worth playing with is this: hold the volume fixed and change the ingredient. The volume never moves, but the weight tracks the density.

Reading and interpreting the result

When the tool returns a weight, treat it as a best estimate, not a physical constant. The density values are household averages. Real flour varies with brand, humidity and how you fill the cup. If you scoop by pushing the cup into the bag, you compress the flour and can pack in 150 g instead of 120 g, a 25% jump. If you spoon flour in loosely and level it, you land near the 120 g figure.

That is why professional recipes specify the method: "spoon and level" or "scoop and sweep". The number the tool gives assumes the standard spooned-and-leveled density. Your scale is the honest referee. If you weigh 2 cups of your own flour and get 260 g, use your own density for future conversions.

Fluid ounces and weight ounces are different things. A "fluid ounce" is a volume (about 29.6 mL). The tool's ounce is a weight (28.35 g). One cup of water is 8 fluid ounces but only about 8.35 weight ounces, and one cup of flour is still 8 fluid ounces yet only 4.2 weight ounces.

Common mistakes

The errors below account for most cooking conversion failures.

Using water density for everything: Assuming 1 cup equals 237 g regardless of ingredient. This overstates flour by nearly double and understates honey by 30%.
Mixing US and metric cups: A US cup is 236.6 mL. A metric cup is 250 mL and an old imperial cup is 284 mL. This tool uses US customary. Using a metric measuring cup with US gram targets adds about 6% error.
Packing versus not packing: Brown sugar is measured packed (220 g/cup); flour is not. Reverse either and you are off by 20% or more.
Confusing fluid and weight ounces: Covered in the warning above. When a recipe says "8 oz", check whether it means a cup of liquid (volume) or a half-pound of solid (weight).

Related converters on this site

If you need conversions beyond the kitchen, the Universal Unit Converter handles length, mass, temperature, pressure and energy with exact factors. For car mileage, the Fuel Economy Converter moves between MPG and L/100 km. For sound and signal ratios, the Decibel Converter turns ratios into decibels and back.

Frequently asked questions

How many grams is a cup of flour?

About 120 grams for all-purpose flour, spooned and leveled. If you scoop directly from the bag you can pack in 140 to 150 grams, so weigh it if the recipe is fussy.

Why does the converter need the ingredient?

Because cups measure volume and grams measure mass, and the ratio between them is density. Flour is 0.507 g/mL, honey is 1.437 g/mL. Without knowing the ingredient there is no single correct answer.

Is a US cup the same as a metric cup?

No. A US cup is 236.6 mL, a metric cup is 250 mL, and an imperial cup is 284 mL. This tool uses US customary units throughout.

How accurate are the weights?

Within a few percent for liquids, which have stable densities. For dry compressible ingredients like flour and powdered sugar, expect up to ±20% depending on how you measure. A kitchen scale removes that uncertainty.

Can I convert tablespoons to grams directly?

Yes. One tablespoon is 14.79 mL, so multiply by the ingredient density. One tablespoon of butter is 14.79 \times 0.959 \approx 14.2 grams; one tablespoon of flour is 14.79 \times 0.507 \approx 7.5 grams.

Try it yourself in the tool