Quick answer
Buttercream tastes better to most people and is faster to apply: an 8 inch, 2 layer cake takes about 5.5 cups with piped borders. Fondant wins for sharp edges, printed designs and long transport, taking about 1.6 lb rolled at an eighth inch for the same cake. Most tiered cakes use both.
Satin Ice Fondant for Cake Decorating, White Buttercream Flavor, 2 lb
Two pounds is about one 8 inch cake with a margin, which is the right quantity to buy until you know fondant suits you, and the buttercream flavour answers the usual complaint about taste.
Best for: a single fondant covered cake
Check price on AmazonButtercream wins on taste and speed for most home bakers: it goes on the same hour it is made, and the sugar-and-butter flavor most people actually want on a slice of cake. Fondant wins on geometry: a rolled sheet gives sharp corners on a square tier, a smooth canvas for printed or painted designs, and a covering that survives hours at room temperature or a bumpy car ride without sliding, none of which buttercream does reliably on its own.
The two are not really substitutes, because fondant is almost never applied straight to cake. A 2 layer, 8 inch round cake first gets a thin buttercream coat underneath, about 3.9 cups, the thinner, firmer coat this site uses as its under-fondant convention rather than a full buttercream finish, since the fondant becomes the visible surface, and then a fondant disc rolled to an eighth of an inch across, which works out to about 1.62 lb for the same cake. The fondant number is a physical calculation from the disc's diameter and thickness; the buttercream number is the site's own surface area convention at the reduced under-fondant coat. Run either in the fondant calculator or the frosting calculator.
Fondant or buttercream: what changes with the finish?
The choice usually comes down to what the cake has to survive and what it has to look like, more than which one tastes better.
| Specification | Rolled fondant | Buttercream |
|---|---|---|
| Taste, by consensus of owner reviews | Sweeter, gum-like texture; often scraped off | Preferred by most people as an eaten frosting |
| Sharp corners on a square tier | Yes, its main strength | Difficult without acrylic discs and chilling |
| Printed or painted designs | Smooth, even canvas | Textured surface fights a flat print |
| Time out of refrigeration | Holds for hours at room temperature | Softens sooner in a warm room |
| Application time for an 8 in cake | Longer: roll, drape, smooth, trim | Faster: spread, smooth, pipe |
| Edible waste from trimming | Real; offcuts are usually discarded | Minimal; excess goes back in the bowl |
How much fondant do you need to cover a cake?
Fondant weight is a physical calculation: the disc has to reach across the cake's width, down both sides to the board, and out a couple more inches on each edge to hold and trim while you work.
| Cake size | Fondant disc (in across) | Fondant needed (lb) |
|---|---|---|
| 6 in round | 16.4 | 1.29 |
| 8 in round | 18.4 | 1.62 |
| 9 in round | 19.4 | 1.80 |
| 10 in round | 20.4 | 1.99 |
| 12 in round | 22.4 | 2.40 |
How much buttercream goes under the fondant?
Fondant still needs a coat underneath, both to glue crumbs down and to give the fondant something even to sit on, but it is a thinner job than a fully piped buttercream finish, since the fondant itself becomes the decoration.
| Cake size | Buttercream (cups) |
|---|---|
| 6 in round | 2.5 |
| 8 in round | 3.9 |
| 9 in round | 4.6 |
| 10 in round | 5.4 |
| 12 in round | 7.1 |
Does fondant actually taste worse than buttercream?
By the consensus of verified owner reviews, yes, most people rate plain fondant as noticeably sweeter and more gum-like than buttercream, which is why so many fondant cakes get peeled at the table. Two things narrow that gap without abandoning fondant altogether.
Flavored fondant is the first: Satin Ice's buttercream-flavored white fondant is built to answer this exact complaint, and a two pound block covers roughly one 8 inch cake with a margin, the right quantity to test before committing to a larger tiered project. The second is color: rather than tinting white fondant brown for a chocolate cake, which tends to read as dyed rather than genuinely chocolate, a dark chocolate fondant gives an honest color and flavor without any gel coloring at all. For a full sheet or several tiers, the five pound block is the more economical unit, since it covers roughly three 8 inch cakes with trim to spare.
Before this cake leaves the kitchen
Fondant itself is a sugar paste and does not need refrigeration, but the buttercream underneath does if it uses cream cheese or fresh whipped cream, so the safe storage rule follows whatever is under the fondant, not the fondant on top. A fondant-covered cake can sit at room temperature longer than a bare buttercream cake, since the fondant seals in moisture and shields the coat underneath from air, though it will start to sweat if moved from a cold fridge into a warm, humid room, which is a cosmetic problem rather than a safety one. Ask about allergies before baking for someone else, and if a cake is being sold rather than given away, that is governed by your state's cottage food law, which varies.
What this job actually needs
Satin Ice Fondant for Cake Decorating, White Buttercream Flavor, 2 lb
$20.99Two pounds is about one 8 inch cake with a margin, which is the right quantity to buy until you know fondant suits you, and the buttercream flavour answers the usual complaint about taste.
Best for: a single fondant covered cake
Check price on AmazonAmazon prices move often, so check before you buy.
Ateco 1301 Fondant and Icing Smoother
$7.94The fondant smoother from a trade supplier rather than an unbranded two pack, with a flat face and a square corner for pressing the bottom edge in.
Best for: finishing a fondant covering
Check price on AmazonAmazon prices move often, so check before you buy.
KitchenAid KFE5TS Flex Edge Beater for 4.5 and 5 Quart Tilt-Head Mixers
$49.99A flexible silicone edge that wipes the bowl wall as it turns, which is the single attachment that most improves buttercream, because unmixed butter clinging to the side is what makes a batch look curdled.
Best for: buttercream and creaming butter and sugar
Check price on AmazonAmazon prices move often, so check before you buy.
Questions people ask
- Does fondant taste bad compared to buttercream?
- By the consensus of verified owner reviews, plain fondant reads sweeter and more gum-like than buttercream to most people, which is the most common reason a fondant-covered cake gets peeled off before it is eaten. Buttercream-flavored fondant, a version made specifically to answer this complaint, closes some of that gap. Many decorators solve it by using fondant for shape and buttercream underneath for flavor, since the two are usually layered rather than chosen as a strict either-or.
- How much fondant do I need for an 8 inch cake?
- About 1.62 lb, rolled into a disc roughly 18.4 in across at an eighth of an inch thick, for a 2 layer, 8 inch round cake. That figure comes from the cake's diameter plus twice its height plus a margin on each side to hold and trim while working. Buy a little over this amount, since real trimmings get cut away and discarded rather than reused.
- Can you put fondant directly on a cake without a buttercream layer first?
- Not successfully. Fondant needs something even and slightly tacky underneath to stick to and to hide crumbs, and a bare baked cake surface is neither. A thin buttercream or ganache crumb coat first is standard practice, and it is a lighter coat than a fully finished buttercream cake would need, since the fondant itself becomes the visible decoration rather than the buttercream underneath it.
- How long does a fondant covered cake last without refrigeration?
- Fondant itself is a sugar paste and holds up at room temperature for many hours on its own, but the safe storage time actually depends on what is underneath it. A cake with plain buttercream underneath follows buttercream's own room temperature guidance; a cake with cream cheese frosting or a fresh cream filling underneath needs refrigeration regardless of the fondant on top, since the fondant does not change what the filling is made of.
- Is fondant harder to work with than buttercream?
- Yes, for most home bakers starting out. Fondant takes longer per cake: kneading it pliable, rolling it evenly, draping it without tearing, and smoothing out air bubbles are all skills with a real learning curve, and a mistake usually means starting the covering over. Buttercream forgives mistakes more easily, since a rough patch can be re-spread, which is why most decorators recommend learning smooth buttercream work before attempting a full fondant covering.
Related pages
How this page was put together
Researched from pan geometry, published manufacturer capacities, published serving conventions and university extension guidance. Not hands-on testing, and not professional advice.
Figures are labelled as derived, published or trade convention. Where no honest figure exists, the page says so rather than filling the gap.