Kitchen Conversions

Every conversion on this site is worked from the figures below. They are US measures, because that is what the recipes asking these questions are written in.

Volume: cups, ounces, millilitres

A US cup is 8 fluid ounces by definition, which makes it 237 ml. Every other volume figure follows from that one.

Cups to fluid ounces
CupsFluid ounces
1/4 cup2 fl oz
1/2 cup4 fl oz
1 cup8 fl oz
2 cups16 fl oz
3 cups24 fl oz
4 cups32 fl oz
6 cups48 fl oz
8 cups64 fl oz
Fluid ounces to cups
Fluid ouncesCups
1 fl oz1/8 cup
2 fl oz1/4 cup
4 fl oz1/2 cup
6 fl oz3/4 cup
8 fl oz1 cup
12 fl oz1 1/2 cups
16 fl oz2 cups
32 fl oz4 cups
Litres to cups
LitersCups
1/4 L1.06 cups
1/2 L2.11 cups
1 L4.23 cups
1 1/2 L6.34 cups
2 L8.45 cups
3 L12.7 cups
4 L16.9 cups
Cups to tablespoons
CupsTablespoons
1/4 cup4 tbsp
1/2 cup8 tbsp
1 cup16 tbsp
2 cups32 tbsp
3 cups48 tbsp
4 cups64 tbsp

The cup is not the same everywhere

A US cup is 236.6 ml. A metric cup, used in Australia and New Zealand, is 250 ml. An old UK imperial cup is 284 ml. On one cup the gap is small; on four it is most of an extra cup.

This is the single most common reason a recipe from another country comes out wrong, and it never announces itself — the measurement simply reads as a cup.

Weight: ounces, pounds, grams

These are exact by definition and do not depend on what is being weighed. One pound is 453.59237 grams, and one ounce is a sixteenth of that.

Ounces to grams
OuncesGrams
1/4 oz7.09 g
1/2 oz14.2 g
1 oz28.3 g
2 oz56.7 g
4 oz113 g
8 oz227 g
12 oz340 g
16 oz454 g
Pounds to grams
PoundsGrams
1/4 lb113 g
1/2 lb227 g
1 lb454 g
2 lb907 g
3 lb1,361 g
5 lb2,268 g
10 lb4,536 g
Kilograms to pounds
KilogramsPounds
1/2 kg1.1 lb
1 kg2.2 lb
2 kg4.41 lb
3 kg6.61 lb
5 kg11 lb
10 kg22 lb

Fluid ounces and ounces are different units

They share a name and measure different things. A fluid ounce is a volume, about 29.6 ml. An ounce is a weight, 28.35 g. For water the two nearly coincide, which is exactly why the two get confused.

For flour, oil or honey they diverge sharply. A recipe calling for 8 ounces of flour means 8 ounces on a scale, not one cup — reading it as a cup puts almost double the flour in the bowl.

What a cup of each ingredient weighs

A cup measures space, not weight. What that space weighs depends entirely on what fills it, so this is the table that turns a volume into a weight.

Weight per US cup
Ingredient1 cup1 cup in ounces1 pound gives
All-purpose flour120 g4.23 oz3.78 cups
Granulated sugar198 g6.98 oz2.29 cups
Brown sugar, packed213 g7.51 oz2.13 cups
Confectioners sugar113 g3.99 oz4.01 cups
Butter227 g8 oz2 cups
Long-grain white rice185 g6.53 oz2.45 cups
Rolled oats89 g3.14 oz5.1 cups
Cocoa powder85 g3 oz5.34 cups
Honey340 g12 oz1.33 cups
Whole milk242 g8.54 oz1.87 cups
Water237 g8.35 oz1.92 cups

Every figure above is one level cup, spooned in and swept flat. Scooping straight from the bag packs the cup and can add a fifth again to the weight. That is why bakers who want the same result twice weigh instead of measuring.

Measuring so the number means something

Liquid and dry cups hold the same volume but are built for different jobs. A liquid cup has a spout and headroom so it can be filled to a line and carried. A dry cup is filled to the brim and swept level, which is why it has no spout.

Read a liquid measure at eye level with the cup on the counter. Held up and read from above, the curve of the surface makes it look fuller than it is.

Where rounding is safe: anything savoury you can taste and adjust. Where it is not: bread, pastry and cake, which depend on the ratio of flour to liquid rather than the amount.

Sources