Undersizing a coffee machine is the most common and most expensive mistake in commercial coffee. The machine copes for a few months, trade grows, and then it starts falling behind at exactly the moment you have a queue. Oversizing wastes capital and counter space. Getting it right takes twenty minutes with a calculator and an honest look at your trading pattern.
Start with your busiest hour, not your daily total
Manufacturers quote daily capacity because it is a simple number, but machines fail at peaks, not at totals. A workplace serving 250 drinks a day sounds demanding until you realise they trickle out steadily from 7am to 5pm, which is 25 drinks an hour. A railway kiosk serving the same 250 might push 120 of them between 7.30 and 8.30.
So work out two figures:
- Daily volume on your busiest day of the week, not the weekly average.
- Peak hour volume, the highest number of drinks you need to produce in any sixty minute window.
If you are already trading, your till system has this data. If you are opening, count the footfall of a comparable venue nearby and assume a conversion rate you can defend.
Estimating volume for a new site
Without trading history, use headcount-based rules of thumb and then sanity check them.
- Office or workplace: expect roughly 1.5 to 2.5 drinks per person per working day where coffee is free, and closer to 0.5 to 1 where staff pay.
- Hotel breakfast: around 1.2 to 1.8 drinks per occupied room, concentrated into a two hour window.
- Cafe or takeaway: conversion from passing footfall varies enormously by site; observe rather than assume.
- Care home or similar: volumes are modest but service is clustered around set meal and visiting times.
Capacity bands and what they mean
Rated daily capacity is a guide to how hard a machine is built to work, not a hard limit. Running consistently near the top of a machine’s band shortens its life and leaves you no headroom for growth. As a working rule, buy for around 120 to 150 per cent of your current busiest day.
| Drinks per day | Typical peak hour | Sensible machine |
|---|---|---|
| Up to 30 | Under 10 | Compact bean to cup, tank fill acceptable |
| 30-80 | 10-20 | Mid-range bean to cup, plumbed preferred |
| 80-150 | 20-40 | Larger bean to cup or one/two group espresso |
| 150-300 | 40-80 | Twin-grinder bean to cup or two group espresso |
| 300+ | 80+ | Two or three group espresso, or multiple machines |
The bottlenecks that actually bite
Capacity is a chain, and the machine is only one link. In practice the limiting factor is usually one of these:
- Steam and milk. On a traditional machine, texturing milk takes longer than pulling shots. Boiler capacity and steam recovery decide your real ceiling, because most drinks sold in the UK contain milk.
- Boiler recovery. A machine can produce impressive numbers in short bursts, then stall while the boiler catches up. Sustained output over an hour is the figure that matters.
- Grinder throughput. On bean to cup machines, a single grinder must serve every drink. Twin grinders both increase speed and let you offer decaf or a second blend.
- The person. Taking payment, making the drink and handing it over are all one pair of hands in most small venues. Adding a second till often gains more throughput than a bigger machine.
- Water supply. A tank-fill machine at 200 drinks a day means someone refilling it repeatedly during service. At any real volume, plumb it in.
Do not forget the drinks that are not espresso
Sizing calculations often quietly assume every drink is a latte. Look at your actual mix. If a third of your volume is black filter coffee, a batch brewer can take that load off the espresso machine entirely, and at a lower cost per cup. Conference and breakfast service in particular is far better handled by filter than by making forty americanos one at a time.
The same applies seasonally. Hot drink sales dip in summer, and venues that add cold drinks, milkshakes or slush spread their demand rather than concentrating it all on one machine.
Plan for growth, within reason
Coffee volumes at a new site usually climb for the first twelve to eighteen months as regulars form. Buying a machine that exactly fits opening week means replacing it during your second summer. Equally, buying triple the capacity you will ever need ties up money that would be better spent on a good grinder, proper water filtration and decent beans, all of which improve every cup you sell today.
Headroom of roughly a third above your current busiest day is the balance most operators find comfortable.
A worked example
A 90-desk office wants a machine for a staff kitchen, coffee free to employees. At two drinks per person per day, that is 180 drinks daily. Attendance is around 70 per cent on an average day but 90 per cent on Tuesdays and Wednesdays, so the busiest day is closer to 160. Peaks cluster at 8.30am and 1pm, roughly 35 drinks in the worst hour.
That points to a larger bean to cup machine, plumbed in, ideally with twin grinders so decaf is available without swapping hoppers, and a fresh milk system with a chilled fridge. Buying at the 80 to 150 band would work on paper and disappoint by Christmas.
Get a second opinion before you commit
Sizing is the one decision that is expensive to reverse, so it is worth checking. Send your busiest day figure, your peak hour, your drink mix and your water situation to [ADD EMAIL ADDRESS], or call [ADD PHONE NUMBER], and we will tell you which capacity band fits. Then browse the bean to cup range or the full shop knowing you are looking at the right shelf.