UK Coffee Chain Caffeine Calculator: Costa vs Pret vs Caffè Nero vs Greggs
In 2023, the UK consumer group Which? bought identical drinks — espresso, medium cappuccino, and filter coffee — from five major high-street chains and had the caffeine independently measured. The results weren't close. A medium cappuccino from Costa carried nearly five times the caffeine of the same drink from Starbucks. Same size, same name on the cup, a five-fold difference in what's actually in it.
Which UK coffee chain has the most caffeine? Costa's medium cappuccino topped the test at 325 mg. For single espresso, Pret A Manger came out strongest at 180 mg — six times Starbucks' 33 mg. Greggs and Caffè Nero land in between, and Caffè Nero consistently tested at the lower end of the four.
Pret's espresso and cappuccino tested at the exact same number
Which?'s lab measured Pret's single espresso at 180 mg and its medium cappuccino at 180 mg — identical. That's not a coincidence: Pret's own product description confirms every espresso drink starts from "the same size Pret base," meaning the milk and water added don't change the caffeine at all. Independent testing backs up what Pret says about its own menu.
Compare a drink type
Which? independent lab testing, 2023Figures are from Which?'s independent laboratory testing of real drinks purchased from each chain, published in 2023 — not compiled estimates. Caffeine content can change if a chain reformulates its beans, blend, or recipe since testing.
Same size cup, wildly different caffeine
All five medium cappuccinos below are the same nominal size. This is what independent testing found inside each one.
Why the gap is this big
Which?'s researchers pointed to several stacking factors: most chains use Arabica beans, but some blend in higher-caffeine Robusta; grind size, steeping time, and water temperature all shift extraction; and — most simply — chains use different numbers of espresso shots for what looks like the same size drink. The size on the cup tells you the volume. It doesn't tell you the dose.
Complete comparison table
All five chains, all three drink types
| Chain | Single espresso | Medium cappuccino | Filter coffee |
|---|---|---|---|
| Pret A Manger | 180 mg | 180 mg | 271 mg |
| Costa | 100 mg | 325 mg | Not tested |
| Greggs | 75 mg | 197 mg | 225 mg |
| Caffè Nero | 45 mg | 110–115 mg | Not tested |
| Starbucks (for reference) | 33 mg | 66 mg | 102 mg |
Which? tested filter coffee only at Pret, Greggs, and Starbucks; Costa and Caffè Nero weren't included in that specific category of the study. Starbucks is shown for reference since it was part of the same original test.
Costa's full menu (from official nutrition data)
| Drink | Small | Medium | Large |
|---|---|---|---|
| Latte | 100 mg | 200 mg | 325 mg |
| Cappuccino / Mocha / Americano | 200 mg | 325 mg | 400 mg |
| Flat White | 241 mg (single size, different extraction method) | ||
| Cortado | 141 mg (single size) | ||
Costa's medium cappuccino figure here (325 mg) matches the independent Which? test exactly, which is a useful confirmation that Costa's own published figures and real-world lab testing agree.
What surprises people about UK coffee chain caffeine
- Costa's medium cappuccino carries nearly 5× the caffeine of Starbucks' version — 325 mg against 66 mg, independently measured, not estimated.
- Pret's espresso and cappuccino are identical in caffeine — both measured at 180 mg, confirming Pret's own claim that every espresso drink shares the same base shot regardless of milk added.
- Greggs is a genuine contender, not a budget afterthought — its cappuccino (197 mg) and filter coffee (225 mg) both beat Starbucks by a wide margin and land close to Pret.
- Caffè Nero is consistently the mildest of the four named chains across every drink type tested, despite being a similarly-priced high-street specialty chain.
- The size on the cup tells you almost nothing about the dose. A "medium cappuccino" spans a nearly 5× range in actual caffeine depending purely on which chain made it.
How many UK coffees a day is safe?
The UK NHS and the FDA both point to roughly 400 mg a day as a reasonable ceiling for most healthy adults; the NHS recommends no more than 200 mg a day during pregnancy.
| Drink | Share of 400 mg guideline |
|---|---|
| Caffè Nero cappuccino (110–115 mg) | 28% |
| Pret filter coffee (271 mg) | 68% |
| Costa medium cappuccino (325 mg) | 81% |
| Two Costa medium cappuccinos (650 mg) | 163% — over the guideline |
Which? specifically flagged that two medium Costa cappuccinos in one day comes close to or exceeds levels linked to insomnia, irritability, and increased blood pressure in some research. Pregnant women following the NHS's 200 mg guidance could exceed it with a single Costa medium cappuccino alone. Sensitivity varies a great deal between individuals. Talk to a doctor or pharmacist if you're pregnant, have a heart condition or anxiety disorder, or take medication that interacts with stimulants.
UK coffee chain caffeine: frequently asked questions
Which UK coffee chain has the most caffeine?
It depends on the drink. Costa has the most caffeine in a medium cappuccino (325 mg), while Pret A Manger has the most in a single espresso (180 mg) and filter coffee (271 mg).
How much caffeine is in a Costa cappuccino?
A medium Costa cappuccino was independently measured at 325 mg, the highest of any chain tested in the Which? study — nearly five times more than the same size drink from Starbucks.
How much caffeine is in a Pret A Manger coffee?
A single espresso and a medium cappuccino were both independently measured at 180 mg, and filter coffee at 271 mg, the highest of any chain tested for that category.
How much caffeine is in Greggs coffee?
Greggs' medium cappuccino was measured at 197 mg, its single espresso at 75 mg, and its filter coffee at 225 mg — consistently the second-strongest of the chains tested.
How much caffeine is in Caffè Nero coffee?
Caffè Nero's cappuccino was measured at 110–115 mg and its espresso at 45 mg — the mildest of the four UK high-street chains tested, though still stronger than Starbucks in the same study.
Why does the same size cup have such different caffeine at different chains?
Which?'s researchers point to bean type (some chains blend in higher-caffeine Robusta), grind size, steeping time, water temperature, and most simply, how many espresso shots go into a given size — all of which vary chain to chain even when the cup size and drink name look identical.
Is this data official from each coffee chain?
The core comparison comes from independent laboratory testing commissioned by Which?, a UK consumer rights organization, not from the chains' own marketing. Costa's full size-by-size figures are drawn from its own published nutrition data and independently match the Which? test exactly for medium cappuccino and single espresso.
Sources and method
Core comparison figures (single espresso, medium cappuccino, and filter coffee across Costa, Pret A Manger, Greggs, Caffè Nero, and Starbucks) come from independent laboratory testing commissioned by Which?, the UK consumer rights and research organization, and published in 2023. Costa's full size-by-size menu figures are drawn from Costa's own published nutrition data, cross-checked against the Which? test where the two overlap (medium cappuccino and single espresso both matched exactly).
- Which? — independent laboratory testing of espresso, cappuccino, and filter coffee across five UK high-street chains, 2023
- Costa Coffee — official published nutrition information
- UK NHS — guidance on caffeine intake and pregnancy
- U.S. Food and Drug Administration — Spilling the Beans: How Much Caffeine Is Too Much?
This page is an independent reference and is not affiliated with, endorsed by or sponsored by Costa, Pret A Manger, Caffè Nero, Greggs, or Starbucks. All brand names are trademarks of their respective owners. Coffee chains may reformulate blends or recipes over time, which can change caffeine content since this testing was conducted. Nothing here is medical advice.