How Much Fondant for an 8 Inch Cake?
About 813 g (29 oz) of fondant, rolled 4 mm thick, covers a 4 inch tall 8 inch round cake. Roll it into a circle about 18 inches (46 cm) across so it drapes down the sides with a little to trim.
You need about813 g · 29 oz
Rolled 4 mm thick to an 18 in (46 cm) circle, for an 8 inch round, 4 in tall.
By thickness
| Thickness | Grams | Ounces |
|---|---|---|
| Thin (2.5 mm) Small cakes, a delicate finish | 542 g | 19 oz |
| Standard (4 mm) Most cakes — forgiving to smooth | 813 g | 29 oz |
| Thick (5 mm) Hides lumps; heavier to lift | 1084 g | 38 oz |
By cake height
| Height | Fondant | Roll to |
|---|---|---|
| 3 in tall | 642 g (23 oz) | 16 in (41 cm) |
| 4 in tall | 813 g (29 oz) | 18 in (46 cm) |
| 5 in tall | 1004 g (35 oz) | 20 in (51 cm) |
| 6 in tall | 1215 g (43 oz) | 22 in (56 cm) |
How the amount is worked out
You cannot cover a cake with exactly its surface area — you roll a circle bigger than the cake, drape it and trim the excess. So the calculator works from that circle: the cake's width, plus its height twice for the sides, plus 2 inches to tuck under and trim. The weight is that circle at your chosen thickness, with fondant at about 1.3 g per cm³. It errs on the side of having enough — the trimmings re-roll for decorations.
Other cake sizes
Topping it?
An 8 inch cake takes a 7.5 in (191 mm) edible image. See the 8 inch cake size guide, or open that size in the topper editor — free to design.
Frequently Asked Questions
What size circle do I roll fondant to for an 8 inch cake?
About 18 inches (46 cm) across for a 4 inch tall cake: the width of the cake, plus the height twice over for the sides, plus 2 inches to tuck and trim.
How much fondant for a tall 8 inch cake?
About 1215 g (43 oz) for a 6 inch tall 8 inch cake at 4 mm, rolled to about 22 inches (56 cm).
How thick should fondant be to cover a cake?
About 4 mm suits most cakes and is forgiving to smooth. Go down to 2.5 mm for small cakes or a delicate finish, or up to 5 mm to hide lumps, knowing it is heavier to lift.
Worked out with the same model as the fondant calculator, so this page and the calculator always agree. CakeyTops calculators are free to use with no account.