What is the ratio for thick icing glaze?

A thick coating glaze (glace icing) uses roughly 100g icing sugar to 1 tablespoon (15ml) of liquid — about a 6 to 7 to 1 ratio by weight. For example, 200g icing sugar to roughly 30ml water. Add the liquid a few drops at a time until the icing is just thick enough to coat the back of a spoon and set with an opaque, smooth finish. The old "200g to 100ml" rule of thumb is far too wet and will run straight off the cake.

What is the difference between a glaze and royal icing?

A glaze is simply icing sugar mixed with liquid and sets to a thin, shiny finish. Royal icing uses egg white (or meringue powder) which makes it set much harder and is used for piping decorations and gingerbread houses. A glaze is softer and more transparent.

Can I use lemon juice instead of water?

Yes, lemon juice makes an excellent glaze liquid and adds a subtle citrus flavour. Orange juice, lime juice, and milk all work too. The acidity in citrus juice can help the glaze set slightly firmer. Use the same quantity as you would water.

How do I get a perfectly smooth glaze?

Sift the icing sugar before mixing to remove lumps. Add the liquid gradually, stirring constantly with a fork or small whisk. If the glaze is too thick, add liquid a teaspoon at a time. If too thin, add more sifted icing sugar.

How much glaze do I need per cake or biscuit?

As a rough guide, 100g of icing sugar makes enough thick glaze for about 12 biscuits or the top of one 20cm cake. For a full drizzle over a bundt cake, you will need about 200-250g of icing sugar worth of glaze.

BakeCalcs

Icing Sugar Glaze Calculator

Calculate icing sugar and liquid quantities for a pourable glaze at your chosen consistency.

Icing Sugar

ConsistencyThick coats and sets opaque; thin drizzles transparently

Liquid TypeWater, lemon/orange juice, or milk; citrus juice sets slightly firmer

How We Calculate This

This calculator uses simple sugar-to-liquid ratios to determine how much liquid you need for your desired glaze consistency. The thicker the glaze, the less liquid per gram of sugar.

Consistency Ratios (icing sugar : liquid by weight)

Thick (~6.5:1): Opaque coating that sets firm — ideal for dipping biscuits (about 100g icing sugar to 1 tbsp / 15ml liquid)
Medium (~3.5:1): Pourable glaze that runs slowly — ideal for drizzling over cake tops
Thin (~2.5:1): Translucent wash — ideal for a light drizzle or transparent glaze

Liquid is shown in millilitres and approximated as 1 ml ≈ 1 g (true for water). Milk and citrus juices are very slightly denser, so add the last few drops by eye until the consistency looks right.

Tips

Always sift icing sugar for a smooth result
Add liquid gradually — you can always add more but cannot take it away
Work quickly as the glaze begins to set once applied

Frequently Asked Questions

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Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.