Cooking & Kitchen
Icing Amount Calculator
A rough guide is about 150 g of icing per 20 cm layer, scaled by pan area for other sizes.
Formula
Icing (g) = layers x 150 x (diameter / 20) squared.
How it works
This covers filling between layers plus a coat over the top and sides. A naked or semi-naked finish needs less; thick piped decoration needs more.
Making a little extra is safer than running short mid-cake — leftover icing keeps well in the fridge for a week.
FAQs
Does the icing type change the amount?
Somewhat. Whipped buttercream spreads further than dense ganache, but the estimate is a fair starting point for both.
How much extra should I make?
About 10% extra covers smoothing losses and a small repair if a layer cracks.
Can I use this for cupcakes?
Roughly: one cupcake needs about 25–30 g of icing for a generous swirl.