How much drink to buy for a UK wedding

If your venue lets you bring your own drinks — a marquee, a barn, somewhere that charges corkage — you have to decide how much to buy. Buy too little and the bar runs dry at nine o'clock; buy too much and you are storing forty bottles of fizz in the spare room. The good news is that UK weddings drink in a predictable shape, and the sums are simple once you split the day into its parts.

Split the day into four parts

The drinks reception. Planners' usual rule is two drinks each in the first hour and one an hour after that, so a two-hour reception is about three drinks a head. Most of it is fizz, with beer for those who would rather.

The toast. One glass of fizz each. A 75cl bottle pours six 125ml glasses.

The meal. The rule of thumb is half a bottle of wine a head. Two 175ml glasses is just under that, and some couples find a third of a bottle is plenty, because the people who do not drink wine balance out the people who drink more of it.

The evening bar. About one drink an hour each, split between beer, wine and spirits. If your venue runs a paying bar in the evening, this part is not yours to buy at all.

Not everyone is drinking

Children, drivers, and anyone who does not drink alcohol will have soft drinks instead — at weddings that is often a fifth of the room. Count them for soft drinks at the same rate, rather than leaving them out, and remember evening-only guests drink in the evening and not before.

What that comes to for 100 guests

With a fifth not drinking, a two-hour reception, a glass for the toast, two glasses of wine with the meal and a four-hour evening bar, 100 guests come to about 42 bottles of fizz, 36 of white wine and 36 of red, 9 cases of beer, 3 bottles of spirits, 10 litres of mixers, 50 litres of soft drinks and 100 kilos of ice. The wine and fizz are rounded up to whole cases of six, which costs nothing if you buy on sale or return.

Ice is the one people forget. UK ice suppliers suggest about a kilo a person for drinks, and half as much again if you are chilling the bottles in it too.

Three things that save money

Ask about sale or return. Many UK wine merchants will take back unopened bottles, which makes rounding up safe.

Count what you already have. The gin from the engagement party still counts.

Buy each thing where it is cheapest: fizz and wine from a merchant, beer and spirits from a cash and carry, and mixers, soft drinks and ice from the supermarket.