Buttercream Icing Calculator
Calculate exactly how much butter, icing sugar, and buttercream you need to frost your cake or cupcakes. Perfect for UK bakers, with metric measurements and standard coverage guides.
Buttercream Calculator
Calculate ingredients for perfect UK buttercream
Select the size and shape of the cake or batch of cupcakes you are making.
More layers require more filling buttercream between the sponges.
Naked cakes use less icing, while heavily piped designs require significantly more.
Making multiple cakes? Multiply the recipe by 2, 3, etc.
Your Recipe
UK buttercream ingredient breakdown
Select your cake size, layers, and coverage style, then click Calculate to see exactly how much butter and icing sugar you need.
Baking & Buttercream FAQ
Everything you need to know about making, storing, and applying UK buttercream icing.
The standard UK vanilla buttercream ratio is 2:1 icing sugar to unsalted butter by weight. For example, 500g of icing sugar to 250g of butter. A small splash of milk (about 5% of the total weight) is added to achieve a smooth, spreadable consistency.
For a standard two-layer 8-inch round cake with a crumb coat and smooth finish, you will need approximately 700g of buttercream. This breaks down to roughly 210g of unsalted butter, 455g of icing sugar, and 35ml of milk.
Split buttercream is usually caused by the butter being too cold or too warm. If it’s too cold, gently warm the bowl by wrapping it in a warm towel for a few seconds, then re-whip. If it’s too warm and greasy, chill the bowl in the fridge for 10-15 minutes, then re-whip until smooth.
Yes, buttercream freezes exceptionally well. Place it in an airtight container or a sealed piping bag and freeze for up to 3 months. To use, thaw it in the fridge overnight, then let it come to room temperature and re-whip it with a wooden spoon or electric mixer to restore its smooth texture.
UK buttercream is typically made with unsalted butter and icing (powdered) sugar, resulting in a richer, buttery flavour that crusts slightly. US buttercream often uses a 1:1 ratio, includes a higher proportion of fat (sometimes using shortening or vegetable fat), and is much sweeter and fluffier.
You can make buttercream up to 3 days in advance and keep it in the fridge, or up to 3 months in the freezer. Always bring refrigerated or frozen buttercream to room temperature and re-whip it thoroughly before using to ensure it is smooth and spreadable.
You can flavour buttercream by adding extracts (vanilla, almond, lemon), pastes (coffee, pistachio), or melting and cooling chocolate. For fruit flavours, use reduced fruit purees or freeze-dried fruit powder to avoid adding too much liquid, which can split the buttercream.
Use gel or paste food colouring rather than liquid drops, as liquid can alter the consistency and cause the buttercream to split. Add the colouring a little at a time using a toothpick, and mix thoroughly. Note that the colour will deepen slightly as it sits.