Convert Caster Sugar from Ounces to Cup (US)
How many US cups is 1 ounce of caster sugar?
1 ounce of caster sugar (castor sugar) is 0.13 US cups. 2 ounces of caster sugar is 0.26 US cups. 4 ounces of caster sugar is 0.52 US cups. 6 ounces of caster sugar is 0.79 US cups. Use the converter below for any amount.
- These figures use the US cup (240 ml). A metric cup is slightly larger at 250 ml, so it holds a little more. Use the metric cup converter →
- 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 →
More about measuring Caster Sugar
Caster Sugar substitutes
Ran out? What to use instead of caster sugar →
No scale? The tool below gives a good estimate, but for exact bakes a digital kitchen scale removes the guesswork.
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0.13 Cup (US)Caster Sugar Calculators & Baking Tools
Working with caster sugar? These tools handle the jobs a converter cannot.
- Jam and Marmalade Calculator Check the sugar a batch of preserve needs and how many jars it fills.
- Pan Size Converter Rescale a recipe for a different cake tin size.
- Oven to Air Fryer Converter Match the temperature and time when you swap the oven for an air fryer, fan oven, or slow cooker.
- Recipe Scaler Scale any recipe up or down and keep every ingredient in ratio.
Common Caster Sugar Conversions
Here are the most common caster sugar conversions from ounces to cups (US).
| Ounces | Cups (US) |
|---|---|
| 1 oz | 0.13 cups (US) |
| 2 oz | 0.26 cups (US) |
| 3 oz | 0.39 cups (US) |
| 4 oz | 0.52 cups (US) |
| 5 oz | 0.66 cups (US) |
| 6 oz | 0.79 cups (US) |
| 8 oz | 1.05 cups (US) |
| 10 oz | 1.31 cups (US) |
| 12 oz | 1.57 cups (US) |
For the reverse conversion, see 1 US cup of caster sugar in ounces.
Frequently Asked Questions
- How many US cups is 1 ounce of caster sugar?
- 1 ounce of caster sugar is 0.13 US cups. The conversion is fixed, so 2 ounces is 0.26 US cups and 4 ounces is 0.52 US cups. These whole-ounce amounts are the ones recipes call for most with bulk ingredients, and the figure scales in a straight line as you multiply or divide. Use the converter above for any other amount, or the conversion chart on this page for the common ones. Open the caster sugar converter
- How many US cups is 2 ounces of caster sugar?
- 2 ounces of caster sugar is 0.26 US cups. The conversion is fixed, so 1 ounce is 0.13 US cups and 4 ounces is 0.52 US cups. These whole-ounce amounts are the ones recipes call for most with bulk ingredients, and the figure scales in a straight line as you multiply or divide. Use the converter above for any other amount, or the conversion chart on this page for the common ones.
- What is 4 oz caster sugar in US cups?
- 4 ounces of caster sugar is 0.52 US cups. The conversion is fixed, so 1 ounce is 0.13 US cups and 2 ounces is 0.26 US cups. These whole-ounce amounts are the ones recipes call for most with bulk ingredients, and the figure scales in a straight line as you multiply or divide. Use the converter above for any other amount, or the conversion chart on this page for the common ones.
- What is 6 oz caster sugar in US cups?
- 6 ounces of caster sugar is 0.79 US cups. The conversion is fixed, so 1 ounce is 0.13 US cups and 2 ounces is 0.26 US cups. These whole-ounce amounts are the ones recipes call for most with bulk ingredients, and the figure scales in a straight line as you multiply or divide. Use the converter above for any other amount, or the conversion chart on this page for the common ones.
Related to Caster Sugar
Sugar
Granulated sugar swaps 1:1 for caster sugar in most recipes, though its larger crystals dissolve more slowly. For meringues or smooth sponges, pulse granulated sugar in a food processor for a few seconds to bring it closer to caster's finer grain. See our Sugar converter.
Icing Sugar
Icing sugar is milled far finer and packs much lighter than caster (125 g vs 225 g per cup), so it is not a 1:1 swap. Use it only where a powder works, such as uncooked frostings and dusting, not for creaming into a cake batter. See our Icing Sugar converter.
Brown Sugar
Brown sugar is caster sugar's opposite in the creaming bowl: damp, clumping, and pressed into the cup instead of levelled off. Swap it in and the molasses brings moisture with it, so a sponge built for caster comes out denser, darker, and slower to dry out. See what 1 ounce of brown sugar is in US cups.
Raw Sugar
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.
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