Fondant Recipe Scaler

The calculator hardcodes a 2-inch reduction per tier going up (so a 10-inch base produces an 8-inch second tier and a 6-inch third tier) because that's the standard proportion bakers use for a visually stable, well-balanced tiered cake. It applies this shrink automatically to each successive tier so you only need to enter the base diameter once rather than measuring every tier separately.

After computing each tier's top circle area (πr²) plus its side cylinder area (πdh), the calculator multiplies that combined area by 1.1 to cover draping overlap and trimming. Real fondant application always uses more than the bare geometric minimum because the sheet has to be smoothed down past the base and the excess trimmed away, so the 10% buffer keeps the estimate from running short.

Roll-out diameter tells you how large a circle to roll a single sheet of fondant into before draping over the base tier — it's calculated as the base tier's diameter plus twice its height (to cover both sides going up and over the edge) plus 4 inches of handling margin. Total fondant weight, by contrast, sums the fondant volume needed across every tier's surface area and converts that to weight — the two numbers answer different questions (how big to roll vs. how much to buy).

Yes — thickness feeds directly into the volume calculation (surface area times thickness in inches), so doubling thickness from 2mm to 4mm roughly doubles both the fondant weight and the cost estimate at the flat $5/lb rate. Standard practice is 3mm: thinner sheets look more delicate but tear more easily during draping, while thicker sheets are more forgiving for beginners at the cost of more fondant.