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Fondant, in the right amount

Enter the cake and the overhang, and get the fondant to weigh out and how wide to roll it.

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The cake to cover

Fondant to roll out

738 g

Top and sides at 5 mm, about 26 oz

Roll it out to

18 in (46 cm)

Diameter, to drape and trim

What it costs

Fondant cost

£4.43

At your price per kg

Worked from the surface the fondant has to cover, the top plus the sides, at a steady 5 mm, so a taller or wider cake gets its own answer. Roll to the size above so the sheet reaches the board, then trim once the cake is covered. Warm the fondant soft before you roll.

The fondant is the last layer. BakerInbox keeps your recipes, prices, and orders in one place.

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Fondant to cover, at a glance

Fondant to cover round and square cakes, about 4 in high, rolled to 5 mm
Cake sizeRound (g)Round (oz)Square (g)Square (oz)
6 in508 g18 oz703 g25 oz
7 in619 g22 oz857 g30 oz
8 in738 g26 oz1022 g36 oz
9 in865 g31 oz1198 g42 oz
10 in1000 g35 oz1384 g49 oz
12 in1292 g46 oz1788 g63 oz

A guide for an all-in-one cover at 5 mm. A taller cake, thicker roll, or covered board takes more.

How much fondant to cover a cake

Fondant to cover a cake is worked from the surface it has to reach: the top, the sides, and a little overhang to grip and trim. An 8 in round about 4 in tall takes roughly 750 g rolled to 5 mm. Enter your cake and the calculator works the weight, the roll-out size, and the cost.

The surface

It comes from the surface, not the servings

The fondant a cake takes is set by the surface it has to cover, the top plus the sides, not by how many people it feeds. A taller cake has deeper sides, so it takes more even at the same width. A 10 in round has nearly twice the surface of a 6 in, so it takes nearly twice the fondant. This tool works that area for you and turns it into a weight at a standard 5 mm roll.

Roll it bigger

Roll to the cake, plus twice the height

A single sheet has to drape the top and reach down both sides, so it must be rolled to the cake width plus twice the height, plus a margin to grip and trim. For an 8 in round about 4 in tall that is roughly an 18 in circle. The calculator gives you the exact roll-out size so you cut the fondant once and it reaches the board.

Thickness

About 5 mm, the same every time

Rolled fondant is worked to about 5 mm, thick enough to hide the ganache and take a smooth finish without tearing. Roll it thinner and you use less but risk seams and elephant skin. The weights here assume a steady 5 mm, so the number holds as long as you roll to guides rather than by eye.

Practical

Warm it, and give yourself an inch

Cold fondant cracks, so knead it soft before you roll. Leave about an inch of overhang all round: enough to smooth the top edge and ease the sides down without running short at the base. Trim once the cake is covered. Keep the offcuts sealed and they colour up for decorations.

FAQ

Common questions

How much fondant do I need to cover a cake?

It depends on the surface, not the servings. A standard 8 in round about 4 in tall takes roughly 750 g rolled to 5 mm, a 6 in round about 500 g, a 10 in round about 1 kg. A square takes more than a round of the same size because of the corners. Enter your cake above and the calculator works it exactly.

How much fondant to cover an 8 inch cake?

About 750 g for an 8 in round roughly 4 in tall, rolled to 5 mm. Roll it thinner and you use a little less. An 8 in square takes more, around 1 kg, because the corners add surface and waste. A taller cake takes more again.

How thick should fondant be rolled to cover a cake?

About 5 mm. That is thick enough to hide the ganache underneath and hold a smooth finish without tearing on the edges. Rolled thinner, around 3 to 4 mm, you use less but risk seams showing and the surface creasing. The weights here assume 5 mm, rolled to guides rather than by eye.

How big should I roll the fondant out?

Wide enough to cover the top and drape both sides, so the cake width plus twice the height, plus about an inch each side to grip and trim. For an 8 in round about 4 in tall that is roughly an 18 in circle. The calculator gives you the roll-out size along with the weight.

How much fondant for a square cake?

More than a round of the same size. A square has a larger top and deeper corners, and the corners waste a little as you ease the fondant down, so an 8 in square takes about 1 kg against roughly 750 g for an 8 in round. Enter the shape above and the calculator adjusts for it.

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