1/2 Cup Caster Sugar in Grams
1/2 cup of caster sugar weighs 95 g (spooned and levelled, King Arthur Baking). Fine-grained white sugar that dissolves faster than granulated sugar. All the figures on this page are approximate conversions based on the King Arthur Baking value, so when a recipe really matters, verify with a kitchen scale.
Fine-grained white sugar that dissolves faster than granulated sugar. It is used for meringues, cocktails, shortbread and custards. That range of uses is part of why the conversion comes up so often: the same ingredient appears in everyday cooking and in precise baking, and the two situations demand different levels of accuracy. Knowing the weight of half a cup, rather than guessing from a measuring cup, keeps the result consistent no matter which recipe you are following.
Why weighing half a cup of caster sugar beats measuring it in cups
Sugar looks simple to measure, but it is one of the ingredients where a cup can mislead you most. caster sugar pours and settles differently depending on humidity, crystal size and how long the bag has sat on the shelf, so two cooks measuring 1/2 cup by eye can easily end up 10 g apart. In baking that gap shows up in the crumb, the spread and the browning, because sugar does far more than sweeten: it holds moisture, tenderises gluten and feeds the caramelisation that gives a bake its colour. Weighing 1/2 cup as 95 g takes the guesswork out of all of it, and it is faster than spooning and levelling once the scale is on the bench.
Caster Sugar cups to grams conversion table
| Cups | Grams (approx.) |
|---|---|
| 1/4 cup | 47.5 g |
| 1/3 cup | 63.5 g |
| 1/2 cup | 95 g |
| 2/3 cup | 126.5 g |
| 3/4 cup | 142.5 g |
| 1 cup | 190 g |
| 1 1/2 cups | 285 g |
| 2 cups | 380 g |
| 3 cups | 570 g |
One tablespoon of caster sugar weighs about 12 g, and one teaspoon about 4 g. For small amounts a scale that reads to the gram is far more reliable than a spoon, because a heaped tablespoon can weigh half as much again as a level one. The table is rounded to the nearest half gram, so the numbers are approximate by design; the half-cup figure of 95 g is the one to use when a recipe calls for half a cup.
How the weight was measured
Spooned and levelled means spooning the ingredient into the measuring cup until it is heaped, then sweeping a straight knife across the top to level it off. Never scoop the cup through the bag or jar, and never tap the cup down, because both pack the ingredient and add weight.
The source for the 190 g per cup figure is King Arthur Baking, and the confidence in the value is high. King Arthur Baking publishes a standard ingredient weight chart that recipe developers use as a reference, and this page follows it exactly rather than averaging across sources, because an average of two different measuring methods is a number that matches nobody's cup.
Because caster sugar is measured spooned and levelled, the weight per cup is stable from one kitchen to the next, and the 95 g figure for half a cup is a reliable default. Small differences in brand or temperature shift it by only a gram or two, which is far below the threshold that changes a recipe.
All the figures on this page are approximate conversions. When a recipe really matters, verify with a kitchen scale: weigh the ingredient directly into the bowl on a tared scale and trust that number over any cup.
Worked examples
A batch of drop cookies
A classic drop-cookie recipe calls for 1/2 cup of caster sugar to sweeten a dozen cookies. Weighing 95 g instead of scooping gives you a dough that spreads the same way every time, because the sugar dissolves at the same rate in the butter and the edges crisp evenly. If the recipe is doubled for a school bake sale, use 190 g for 1 cup, and the second batch will match the first.
Halving a cake recipe
Halving a cake that asks for 1 cup of caster sugar leaves you with 1/2 cup, or 95 g. A half-cup measure is small enough that packing and levelling errors are proportionally large, so the scale earns its keep here: 95 g is exact, while a scooped half-cup can be 5 to 10 g heavy and make the crumb gummy.
A quick glaze or syrup
A simple glaze often needs just 1/4 cup of caster sugar, which is about 47.5 g. Weighing such a small amount is far more reliable than eyeballing a quarter-cup measure, and it keeps the glaze from turning gritty or overly sweet.
When this conversion matters most
This conversion matters most in baking, where caster sugar controls moisture, spread and browning all at once. A cake, a cookie or a meringue has no room for a 10 g error, and the smaller the recipe the bigger the error looks as a percentage. It also matters when you are following a recipe from another country, because most of the world bakes in grams and a cup is an American habit. Converting to grams lets you use any recipe from any source with the same confidence.
Common mistakes with caster sugar
- Scooping straight from the bag. Pushing the cup into the sugar compresses it and can add several grams per half-cup. Spoon the sugar into the cup and level it off, or better, weigh 95 g on a scale.
- Measuring packed sugar the same as loose sugar. Brown and muscovado sugars are packed, while granulated sugar is spooned and levelled. Using the wrong method for caster sugar changes the weight by a fifth or more.
- Trusting a cup for a half-cup. Small measures amplify error: a heaped half-cup can be 10 g heavy. Weighing 95 g removes the problem entirely.
- Forgetting humidity. Sugar absorbs moisture from the air, so a cup of caster sugar weighs more on a damp day. A sealed container and a scale keep the recipe honest.
Storage and handling
Airtight container, cool and dry, indefinitely. Keeping caster sugar stored properly also keeps its weight per cup stable: an ingredient that has absorbed moisture from the air weighs more per cup than a dry one, so good storage is not just about freshness, it is about measurement accuracy too. If a container has been open for months in a humid kitchen, the first thing to do before a precise bake is to weigh the ingredient rather than trusting the cup.
Frequently asked questions
How many grams is 1/2 cup of caster sugar?
1/2 cup of caster sugar weighs 95 g, measured spooned and levelled according to King Arthur Baking. That is the figure to use when converting a recipe from cups to grams, and it is the value the conversion table on this page is built on.
How do I measure caster sugar without a scale?
Spooned and levelled means spooning the ingredient into the measuring cup until it is heaped, then sweeping a straight knife across the top to level it off. Never scoop the cup through the bag or jar, and never tap the cup down, because both pack the ingredient and add weight. That gives the closest result to 95 g per half-cup, but it is still an estimate: the honest answer is that a scale is the only way to know the exact weight, and a basic digital kitchen scale costs less than a bag of good flour.
Can I use caster sugar and granulated sugar interchangeably by weight?
Only with care. Different sugars have different weights per cup and different flavours, so swapping by volume is unreliable. Swapping by weight is better, but a sugar with more molasses, like brown or muscovado, also adds moisture and acidity, which changes how the bake behaves. For a straight swap, match the weight and expect a slightly different flavour and colour.
What is caster sugar used for?
Meringues, cocktails, shortbread and custards. Fine-grained white sugar that dissolves faster than granulated sugar.
Does 1/2 cup of caster sugar always weigh 95 g?
No. Brand, crystal size, moisture and how settled the container is all shift the weight by a few grams. The 95 g figure is the standard King Arthur Baking value for caster sugar measured spooned and levelled, and it is the right default, but when a recipe is precise, weigh the ingredient and trust the scale over the cup.
How should I store caster sugar?
Airtight container, cool and dry, indefinitely. Good storage keeps the ingredient fresh and keeps its weight per cup consistent, because moisture absorbed from the air adds grams that the recipe did not ask for.
Related conversions
Use the sugar substitute converter or the cups to grams converter for instant answers, or browse the cups to grams hub for the full ingredient list. Related pages: 1/2 cup granulated sugar in grams, 1/2 cup brown sugar in grams, 1/2 cup powdered sugar in grams. More tools: cups to grams converter, grams to cups converter, recipe scaler. See also our disclaimer about approximate conversions.