The Ultimate Cake Portion Guide: How Much Cake Do You Really Need?

It's one of the most common questions we hear at BKRY, and it's a completely reasonable one to ask: how much cake do I actually need?

Order too little and you'll have guests going without. Order too much and you'll be eating Victoria sponge for a fortnight. Getting the portions right is one of those things that feels complicated until someone lays it out clearly, so that's exactly what we're going to do.

Why cake portions aren't straightforward

The right amount of cake depends on a few things:

• The occasion. A wedding or formal celebration is typically served in smaller, neater slices than a casual birthday party.
• What else is being served. If cake is the dessert, portions will be larger. If it follows a full meal, smaller slices usually suffice.
• Your guests. A children's party will have different consumption patterns to a 50th birthday gathering of adults.

With that in mind, here's a guide to how our BKRY cakes portion up.

Understanding our cake sizes

At BKRY, our celebration cakes come in four sizes. Each one refers to the diameter of the cake and the number of sponge layers inside, which affects both the height and the number of portions you'll get.

6 inch Short (2 layers): Our most compact option. A lovely choice for smaller gatherings, intimate celebrations, or as a centrepiece when you're also serving other desserts.

6 inch Midi (3 layers): The same footprint as the Short but with an extra layer of sponge and filling, giving you a more generous, impressive-looking cake. A great all-rounder.

6 inch Tall (4 layers): Our tallest 6 inch option. Four layers of sponge make this a real showstopper, and it portions up significantly more than it might appear at first glance.

8 inch Tall (4 layers): Our largest celebration cake. With a wider base and four generous layers, this is the right choice for bigger gatherings, milestone birthdays and any occasion where you want the cake to make a real statement.

Number cakes: Our number cakes are a completely different format, made up of shaped sponge layers filled and decorated to form a number. Because the shape varies, portions work differently. As a rough guide, a single number cake comfortably serves 15 to 20 people as a dessert portion, making them ideal for milestone birthdays where the number itself is part of the celebration.

Portion guide

The portions below are based on a standard dessert slice. If you're serving cake as one of several desserts or at a buffet-style event, you'll comfortably get more portions from each size.

Which size is right for my occasion?

Small gathering or family celebration (up to 10 guests): The 6 inch Short is a beautiful option and avoids waste. If you'd like a little extra height and drama, step up to the Midi.

Birthday dinner or casual party (10–15 guests): The 6 inch Midi or Tall will see you through comfortably, with a few slices to spare.

Bigger birthday party or celebration (15–25 guests): The 6 inch Tall or 8 inch Tall is your best option here. If you're also serving other food and expect some guests to skip cake, the Tall 6 inch may well be enough.

Larger gathering (25 or more guests): The 8 inch Tall is our largest option and will serve a good-sized group. If your guest list is significantly larger than 25, we'd suggest supplementing with a batch of matching cupcakes, which makes serving much easier and keeps everything looking cohesive on the table.

Milestone birthday (any size): A number cake is a brilliant choice for milestone ages, particularly 18ths, 21sts, 30ths and 40ths. They're visually striking, personal and always get a reaction. Pair with cupcakes if you're catering for a larger group.

Our top tips for getting it right

When in doubt, go one size up. Leftover cake is never a problem. Running out always is.

Factor in cutting waste. There's always a little loss when a cake is cut on the day: crumbs, uneven slices, the end pieces. A small buffer is always sensible.

Talk to us. When you order from BKRY, just tell us your guest numbers and the occasion and we'll help you find the right size. There's no guesswork required on your part. We do this every day.

Add cupcakes to the mix. A celebration cake as the centrepiece alongside a batch of matching cupcakes is one of the best ways to cater for a crowd. It looks stunning, serves more people, and means no one has to wait around while the cake is being cut and plated.

Order your celebration cake from BKRY

All of our cakes can be fully customised for your occasion, from flavour and finish to colours and personalised toppers. Order online for collection from our Caversham bakery in Reading, or pop into the shop on Church Street if you'd like to chat through what's right for your celebration.

We're here to make sure no one leaves the table without a slice