How much ganache do you need?
Pick the chocolate and what it is for, enter the cake, and get the chocolate and cream to weigh out.
Free. No signup needed.The short answer
A three layer 8 inch round under fondant takes just under 1 kg of ganache: roughly 650 g dark chocolate and 325 g double cream at 2 to 1. Enter your own tiers below for the exact amount, and what to buy.
How much ganache do you need?
BakerInbox
The ganache
The cake to cover
Ganache to make
1.07 kg
Dark, under fondant, 10% extra in
Chocolate
716 g
2 parts
Double cream
358 g
1 part
What to buy
Chocolate to buy
3 bags
900 g in
Cream to buy
2 cartons
600 ml in
Ganache cost
£8.10
On whole bags and cartons
Worked from the surface the ganache has to cover, at an under-fondant thickness, so a taller or wider cake gets its own answer. Ratios are by weight, never by volume. The 10% extra is already in, and the cost is on whole bags and cartons, the way you actually buy.
Costing the ganache is half the job. BakerInbox keeps your recipes and prices in one place.
Start free trialHow much ganache per cake size
| Round cake, 3 layers | Ganache to make | Dark chocolate | Double cream |
|---|---|---|---|
| 6 in | 625 g1 lb 6 oz | 415 g15 oz | 210 g7.3 oz |
| 8 in | 970 g2 lb 2 oz | 650 g1 lb 7 oz | 325 g11 oz |
| 10 in | 1395 g3 lb 1 oz | 930 g2 lb 1 oz | 465 g1 lb |
| 12 in | 1885 g4 lb 2 oz | 1255 g2 lb 12 oz | 630 g1 lb 6 oz |
| About 4 in tall, covered under fondant, 10% extra included. Milk and white chocolate set softer, so use 3 parts chocolate to 1 part cream: the calculator splits it for you. | |||
Ganache ratios at a glance
| Use | Chocolate to cream | Why |
|---|---|---|
| Dark, under fondant | 2 : 1 | Sets firm, holds a sharp edge |
| Milk, under fondant | 3 : 1 | Milk chocolate is softer, so more of it |
| White, under fondant | 3 : 1 | Same again for white chocolate |
| Dark, filling | 1 : 1 | Soft and spreadable once cooled |
| Drip | 1 : 1 | Warm, pourable, sets on the cake |
| Whipped | 1 : 2 | Chill, then whip to a light filling |
Made with BakerInbox. Free cake tools at bakerinbox.com/tools
Ganache ratios and coverage
Ganache is chocolate and cream by weight: two to one for a firm dark coat under fondant, three to one for softer milk or white, one to one for a filling or a drip.
The ratio
Chocolate to cream, always by weight
Ganache is a ratio of chocolate to cream measured on the scales, never in cups. Dark chocolate sets firm at two parts chocolate to one part cream, which is why it holds a sharp edge under fondant. Milk and white are softer and sweeter, so they need three to one to set as firm. For a filling or a drip, one to one stays soft and pourable.
The amount
How much comes from the surface, not the servings
The amount of ganache a cake takes is worked from the surface it has to cover and fill, not from how many people it feeds. A 12 in cake has nearly three times the surface of an 8 in, so it takes nearly three times the ganache. This tool works the area for you at an under-fondant thickness, then splits it into chocolate and cream at your chosen ratio.
Under fondant
A firm dark ganache is what holds the edge
The reason a ganached cake has crisp corners under fondant is the firm set of a two to one dark ganache. It chills hard, takes a sharp scrape, and gives the fondant a flat, cold surface to go onto. Milk and white can go under fondant too, but only at three to one, or they stay too soft to hold the shape.
Practical
Make about 10% more, and let it firm up
Ganache clings to the bowl and the spatula, and a coat that comes up short means melting a fresh batch at a different temperature. Make about a tenth more than the number says. Let it sit until it is thick and spreadable before you coat, not warm and runny.
FAQ
Common questions
What is the ratio for ganache under fondant?
Two parts dark chocolate to one part double cream, by weight. It sets firm enough to hold a sharp edge. Milk and white chocolate are softer, so they need three parts chocolate to one part cream to set as hard.
How much ganache do I need to cover a cake?
It depends on the surface, not the servings. A three layer 8 in round takes roughly 800 g to 1 kg to fill and cover under fondant, more if you build it tall. Enter your cake above and the calculator works the area and splits it into chocolate and cream.
Why measure ganache by weight and not cups?
A cup of chocolate and a cup of cream are very different weights, so measuring by volume breaks the ratio and the ganache sets wrong. Weigh both on the same scale and the set is reliable every time.
Can I use milk or white chocolate under fondant?
Yes, at three to one rather than two to one. Milk and white have more sugar and milk solids and less cocoa butter, so they need more chocolate to the cream to set firm enough to hold an edge.
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