Fondant Diameter Calculator

Fondant Diameter Calculator

Created by Team y2calculate

Content written by James (Ph.D.)

Coding and design by Marcelino (Ms)

Reviewed by David (Ph.D.)

Fact checked 🔍✓

Published: January 21, 2024 → Last Updated: February 5, 2024

Table of Contents

What is fondant?

Fondant is a type of icing or decorative sugar paste commonly used in cake decorating to cover cakes and create a smooth, polished surface. It is a pliable and versatile substance that can be rolled out and draped over cakes, providing a clean and elegant finish.

Formula to calculate Fondant diameter

Here’s the formula for calculating fondant diameter, written in simple terms:

  1. Measure the cake’s diameter across the top, from edge to edge.
  2. Measure the cake’s height from the bottom to the top.
  3. Double the cake’s height.
  4. Add the doubled height to the cake’s diameter.
  5. This final number is the diameter of the fondant you’ll need to cover the cake.


  • If your cake is 20 cm wide and 10 cm tall:
    • 20 cm (diameter) + 20 cm (doubled height) = 40 cm (fondant diameter)

How the fondant diameter calculator work?

The fontant diameter calculator work on a simple formula given below.


In above formula CD is the cake diameter and CH is the cake height.

User will need to enter the cake diameter and cake height. The calculator will automatically calculate the fondant diameter. for the user convenience we have added labels for unit selection, as different users have different parament for measurement, so you can enter cake diameter in cm, inch and feet and same for cake height

Some example

Lets say we have cake diameter as 15 inches and cake height as 25 inches, we will simply calculate the fondant diameter in given steps.

step 1) first we will multiply cake height in inches with 2

step 2) In 2nd step we will add the value to cake diameter 



FD=65 inches  

why do we calculate fondant diameter

Essential Reasons:

  • Ensures proper coverage: Prevents gaps or tearing by providing enough fondant to cover the entire cake smoothly.
  • Minimizes waste: Optimizes fondant use by calculating the correct amount, avoiding excess or insufficient material.
  • Achieves a professional look: Using the right amount of fondant results in a seamless, polished finish without bulkiness or seams.
  • Simplifies the covering process: Knowing the correct diameter allows for efficient rolling and covering, saving time and effort.
  • Enhances precision: Promotes accuracy and consistency in covering, especially for complex designs or multi-tiered cakes.

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