Convert Caster Sugar from Cup to Cup (US)

How many US cups is 1 cup of caster sugar?

1 cup of caster sugar (castor sugar) is 1.04 US cups. 2 cups of caster sugar is 2.08 US cups. 1/2 cup of caster sugar is 0.52 US cups. 1/4 cup (0.25 cup) of caster sugar is 0.26 US cups. Use the converter below for any amount.

  • These figures use the metric cup (250 ml). A US cup is slightly smaller at 240 ml, so it holds a little less.
  • These figures use the US cup (240 ml). A metric cup is slightly larger at 250 ml, so it holds a little more.
  • Cup sizes are not standard worldwide, so the same cup of an ingredient can weigh more or less depending on the country. What is a cup measurement →

Caster sugar, also known as superfine or castor sugar, is a key ingredient in many baking recipes due to its fine texture and quick-dissolving properties. Commonly used in cakes, meringues, and desserts, it sits between granulated sugar and powdered sugar in terms of texture. One metric cup (250 ml) of caster sugar weighs around 225 grams or 7.94 ounces.

Since baking is a precise science, even small differences in sugar quantity can affect the final outcome, from texture and sweetness to structure. This page helps you convert caster sugar between grams, cups, tablespoons, and more so that you can follow any recipe confidently, no matter what measurement system it uses.

Also known as

  • castor sugar
  • Superfine Sugar
  • Baker's Sugar
  • Bar Sugar

Standard granulated sugar has larger crystals than caster sugar, so it dissolves more slowly in batters and meringues. They are close in weight (200 g vs 225 g per cup) and swap 1:1 by volume in most recipes, though caster gives a smoother result. See our Sugar converter.

Raw sugar has large, coarse crystals that dissolve slowly, the opposite of fine caster sugar. It packs lighter (200 g vs 225 g per cup), so it is not a 1:1 swap by volume; weigh when substituting. See our Raw Sugar converter.

Out of caster sugar? See caster sugar substitutes →

No measuring cups? The tool below gets you close, and a measuring cup set keeps every batch the same.

Caster Sugar Measurement Converter

Enter a value and pick your units.

Result

0 Cup (US)

Common Caster Sugar Conversions

Here are the most common caster sugar conversions from cups to cups (US).

CupsCups (US)
0.25 cups0.26 cups (US)
0.5 cups0.52 cups (US)
0.75 cups0.78 cups (US)
1 cup1.04 cups (US)
1.25 cups1.3 cups (US)
1.5 cups1.56 cups (US)
2 cups2.08 cups (US)
2.5 cups2.6 cups (US)
3 cups3.13 cups (US)

Caster Sugar Conversion Chart

The conversion chart below gives a quick reference for converting caster sugar from Cup to Cup (US) and other measurements.

cupcup(US)gramsouncestbsptsp
0.25 cup0.26 cup (US)56.25 g1.99 oz4.17 tbsp12.5 tsp
0.5 cup0.52 cup (US)112.5 g3.97 oz8.33 tbsp25 tsp
1 cup1.04 cup (US)225 g7.94 oz16.67 tbsp50 tsp
2 cup2.08 cup (US)450 g15.88 oz33.33 tbsp100 tsp

This is a volume conversion, so the result is the same for every ingredient. Use the cups to cups (US) volume converter to switch between cups, tablespoons, teaspoons, and millilitres without weighing.

Frequently Asked Questions

How many US cups is 1 cup of caster sugar?
1 cup of caster sugar is 1.04 US cups. The ratio is fixed, so 2 cups of caster sugar is 2.08 US cups and 0.5 cups is 0.52 US cups. Use the converter above for any quantity, or check the conversion chart on this page for the most common amounts at a glance. Open the caster sugar converter
How many US cups is 1.5 cups of caster sugar?
1.5 cups of caster sugar is 1.56 US cups. The ratio is fixed, so 1 cup of caster sugar is 1.04 US cups and 2 cups is 2.08 US cups. Type any other amount into the converter above for the exact figure, or use the chart below for the common ones.
How many US cups is 2 cups of caster sugar?
2 cups of caster sugar is 2.08 US cups. Conversions scale in a straight line, so halving or doubling a recipe keeps the same ratio. 1 cup of caster sugar is 1.04 US cups, and you can multiply or divide that figure to match whatever your recipe needs. Enter any amount in the converter above for an exact US cups reading.
How many cups of caster sugar is 1.04 US cups?
1.04 US cups of caster sugar is 1 cup. The conversion works the same in reverse, so you can switch between US cups and cups without changing the result. This helps when a recipe lists cups but you would rather weigh or measure in US cups. The converter above and the chart below cover both directions for any amount.
How many US cups is 1 cup of castor sugar?
Castor sugar is another name for caster sugar, so 1 cup of castor sugar is 1.04 US cups, exactly the same as caster sugar. The figure does not change with the name: 2 cups is 2.08 US cups and 0.5 cups is 0.52 US cups. Use the converter above for any quantity, or read the conversion chart on this page for the most common amounts.
Are caster sugar and castor sugar the same thing?
Yes. Castor sugar is another name for caster sugar, so they are the same ingredient and convert identically. 1 cup of caster sugar is 1.04 US cups under either name, and 2 cups is 2.08 US cups. Recipes use the two names interchangeably, so you can follow either one without changing quantities or weighing any differently.
What is 1/2 cup caster sugar in US cups?
1/2 cup of caster sugar is 0.52 US cups. The ratio is fixed, so 1 cup of caster sugar is 1.04 US cups and 2 cups is 2.08 US cups. Half measures come up often when scaling a recipe down, and the figure divides cleanly. Use the converter above for any other amount, or the chart below for the common ones.
What is 1/4 cup caster sugar in US cups?
1/4 cup (0.25 cup) of caster sugar is 0.26 US cups. The ratio is fixed, so 1 cup of caster sugar is 1.04 US cups and 2 cups is 2.08 US cups. Quarter amounts often come up when scaling a recipe down step by step, and the figure divides cleanly. Use the converter above for any other quantity, or the chart below for the most common amounts.

Other Ingredients

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