RecipeScan › Grams in a Cup of Sugar

How many grams
in a cup of sugar?

Not all sugars weigh the same — not even close. Caster sugar is 200g per cup. Icing sugar is only 120g. Packed brown sugar is 213g, but unpacked is 165g. Jump straight to what you need.

All Sugar Types White & Brown UK & US Names Packed vs Unpacked
🍚 White sugars — 1 cup
Fine crystals, dry, no molasses. Weight is stable and predictable.
🍚
Caster
200g
per cup
🍚
Granulated
200g
per cup
☁️
Icing (unsifted)
120g
per cup
☁️
Icing (sifted)
100g
per cup
🌾
Demerara
200g
per cup
🥥
Coconut
180g
per cup
🟫 Brown sugars — 1 cup
Contain molasses — sticky, clumpy, must be packed. Weight varies significantly by how you fill the cup.
🟫
Light brown (packed)
213g
per cup
🟫
Light brown (loose)
165g
per cup
🟫
Dark muscovado (packed)
170g
per cup
🟫
Dark brown (packed)
180g
per cup
🟫
Maple sugar
180g
per cup
🌾
Golden caster
200g
per cup

Cups of Sugar to Grams

Select your sugar type — including packed or unpacked for brown sugars — and enter the number of cups.

Enter an amount above to see the result
White Sugars

White Sugar Quick Reference

Dry, free-flowing sugars — weight is consistent and predictable.

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Brown Sugars

Brown Sugar — The Packed Problem

Brown sugar contains molasses. That changes everything about how you measure it.

Light brown sugar
~3.5% molasses
213g
per packed cup
Dark muscovado
~6.5% molasses
170g
per packed cup
⚠️ Packed vs Unpacked — A 30% Difference
213g
1 cup packed
vs
165g
1 cup unpacked
The molasses in brown sugar is hygroscopic — it absorbs moisture from the air, making the sugar sticky and clumpy. This is what causes it to pack so tightly and why the difference between packed and loose is so dramatic.

Packed means pressing the sugar firmly into the cup with your fingers until it holds the cup's shape when turned out — like a sandcastle. Almost every recipe means packed unless it specifically says "loosely packed" or "unpacked".

Using unpacked brown sugar where packed is intended means 23% less sugar — enough to noticeably affect sweetness, moisture, and texture in cookies, brownies, and banana bread.
⚠️ Light vs Dark Brown Sugar — Not the Same Thing
Mild caramel
Light brown · 3.5% molasses
vs
Deep toffee
Dark brown · 6.5% molasses
Light brown sugar (soft brown sugar in the UK) has a mild, gentle caramel flavour. Dark brown sugar (dark muscovado in the UK) has an intense toffee and molasses flavour and makes bakes noticeably moister and chewier.

The higher molasses content in dark brown sugar makes it hygroscopic — it actively draws moisture into your bake. This is why chocolate chip cookies made with dark brown sugar stay chewier for longer than those made with light.

Substituting one for the other: fine in most recipes — just expect a stronger or milder flavour. For a closer match: add 1 tsp molasses per cup of light brown sugar to approximate dark.
💡 How to Stop Brown Sugar Going Rock Hard
Brown sugar hardens when it loses moisture — the molasses dries out and the crystals fuse. To prevent it: store in an airtight container with a terracotta sugar saver or a slice of bread (replace every few days).

To rescue hardened brown sugar: place it in a bowl with a damp (not wet) paper towel, cover, and microwave in 20-second bursts. Or leave overnight with a slice of apple in a sealed bag.

For baking: hardened brown sugar that's been softened works just fine — it hasn't changed chemically, only physically.
💡 UK vs US Brown Sugar Names
Soft light brown sugar (UK) = light brown sugar (US) — ~3.5% molasses, mild flavour.

Dark muscovado (UK) = dark brown sugar (US) — ~6.5% molasses, intense flavour. Muscovado is an unrefined cane sugar; US dark brown is usually white sugar with added molasses — close but not identical.

Light muscovado (UK) = light brown sugar (US) — similar to soft light brown but with a slightly more complex flavour.

Demerara (UK) = raw sugar / turbinado (US) — large golden crystals, partially refined. Crunchy texture, used for toppings and crumbles. Does not behave like soft brown sugar in baking.

Brown Sugar Quick Reference

All weights assume packed unless stated.

Full Sugar Conversion Table

All common sugar types — cups to grams. Brown sugar rows highlighted.

Sugar type ¼ cup ⅓ cup ½ cup 1 cup 2 cups
Caster sugar (granulated)50g67g100g200g400g
Icing sugar — unsifted30g40g60g120g240g
Icing sugar — sifted25g33g50g100g200g
Demerara sugar50g67g100g200g400g
Coconut sugar45g60g90g180g360g
Golden caster sugar50g67g100g200g400g
Light brown sugar — packed53g71g107g213g426g
Light brown sugar — unpacked41g55g83g165g330g
Dark brown sugar — packed45g60g90g180g360g
Dark muscovado — packed43g57g85g170g340g
Maple sugar45g60g90g180g360g

Highlighted rows are brown sugars. All brown sugar weights assume packed unless stated.

The Gotchas

Sugar measurement mistakes that affect baking results.

⚠️ Icing Sugar Weighs Half What You'd Expect
200g
1 cup caster sugar
vs
120g
1 cup icing sugar
Icing sugar is ground to an extremely fine powder — far less dense than caster or granulated. A cup of icing sugar contains 40% less sugar by weight than a cup of caster sugar.

Never substitute icing sugar for caster sugar by volume. You'll have 40% less sweetness, and icing sugar contains cornstarch which affects the bake structure.

Sifted vs unsifted matters too: 1 cup sifted icing sugar = ~100g; 1 cup unsifted = ~120g.
💡 UK vs US White Sugar Names
Caster sugar (UK) = superfine sugar (US) — fine crystals, dissolves fast, best for cakes and meringues.

Granulated sugar (UK/US) — coarser crystals. Interchangeable with caster in most baking, slower to dissolve.

Icing sugar (UK) = powdered sugar / confectioners' sugar (US) — very finely ground with a small amount of cornstarch. Identical products.

Demerara (UK) = raw sugar / turbinado (US) — large golden crystals, residual molasses, crunchy. Used in crumbles and coffee, not in cake batters.
💡 Can You Substitute Caster Sugar for Granulated?
In most baking, yes. Both weigh 200g per cup. The difference is crystal size — caster dissolves faster.

Use caster for: meringues, cold mousse, and any mixture where dissolving without heat matters.

Either works for: cakes, biscuits, crumbles, anything going in the oven. Heat dissolves both equally.

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