How much caffeine is in a cup of coffee?
About 100 to 140 mg in a mug. But café coffee varies far more. In one Glasgow test, a single espresso held 322 mg, more than two mugs. One thing likely explains most of it.
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How much caffeine is in a cup of coffee?
The UK’s Food Standards Agency (FSA) says a mug of coffee has about 100 to 140 mg of caffeine, though this can vary widely.
The NHS puts a cup of instant at 100 mg. It says filter coffee and coffee from coffee shops can contain more.
| Drink | Caffeine | Who says |
|---|---|---|
| Mug of coffee | About 100 to 140 mg | FSA. Can vary widely. |
| Cup of instant coffee | 100 mg | NHS. Filter and coffee shop coffee can contain more. |
| Espresso (60 ml) | About 80 mg | EFSA, the EU food safety body. |
| Cup of filter coffee (200 ml) | About 90 mg | EFSA. |
| Decaf coffee (about 470 ml) | 0 to 13.9 mg | US coffee shop test. |
| Mug of tea | About 75 mg | FSA. |
Sources: FSA; NHS; EFSA; McCusker 2006
EFSA says all its figures are approximate, as caffeine and cup sizes vary. So treat each number as a rough guide, not a label.
For a quick count at home, call each mug of coffee 100 to 140 mg.
Why does café coffee have more caffeine?
Researchers in Glasgow tested 20 espressos from high street cafés. The most caffeinated held 322 mg in one shot, and three more held over 200 mg.
That one thing is how much ground coffee goes in. The team said the amount of beans the barista uses is likely the main reason shots differ.
The bean matters too. Robusta beans often hold more caffeine than arabica, and some blends mix the two.
Sources: NHS; FSA; Crozier 2012
Cafés often make lattes and cappuccinos by adding milk to a single or double shot. More shots means more caffeine, whatever the size of the cup.
The same drink can change day to day. One US café’s large coffee (about 470 ml) ranged from 259 to 564 mg over six days.
Want less? Ask for a single shot, or make one of your coffees a decaf.
How many coffees is 200 mg of caffeine?
About two cups of instant, at the NHS figure of 100 mg each. A café espresso could pass it on its own.
Pregnant? The NHS says to have no more than 200 mg a day. Too much caffeine has been linked to a higher chance of miscarriage and stillbirth.
For other healthy adults, EFSA says single doses up to 200 mg do not raise safety concerns. Across a day, the FSA says up to 400 mg is unlikely to cause harm for most people.
- 200 mg or belowWithin the NHS 200 mg pregnancy limit.
- Above 200 up to 400 mgUnlikely to harm most adults. Over the pregnancy limit.
- Above 400 to just under 1200 mgOver the FSA’s 400 mg a day.
- 1200 mg or aboveFSA: serious effects seen around 1,200 mg.
Sensitive to caffeine, or have a health condition? You may get jittery or anxious on less.
Timing counts too. EFSA says 100 mg may affect sleep in some adults, especially close to bedtime. See when to stop caffeine for sleep.
Does decaf coffee have caffeine?
Yes, a little. Decaf from 10 US coffee shops held 0 to 13.9 mg in a large cup of about 470 ml. Decaf espresso from one shop held 3.0 to 15.8 mg a shot.
That’s a small slice of a 100 mg mug. Switching even one mug a day to decaf takes most of its caffeine out.
Told by a doctor to cut caffeine out fully? Ask them if decaf is fine, since it is not always zero.
How to keep track of your caffeine
The FSA’s limits cover all sources, not just coffee. For adults in the UK, tea is the main source of caffeine, not coffee.
Five ways to count your caffeine
- Count a mug of coffee as 100 to 140 mg, and a mug of tea as about 75 mg.
- Add every source: tea, cola, energy drinks, chocolate and caffeine supplements count too.
- Want less caffeine in a café? Ask for a single shot, or make one of your coffees a decaf.
- Keep to 200 mg a day or less if you’re pregnant.
- Sleeping badly? The NHS says stop tea and coffee at least 6 hours before bed.
Sources: FSA; NHS; NHS insomnia
Wondering if your coffee habit is good or bad for you? See is coffee good for you.
Having a blood test soon? Read coffee before a blood test.
When to speak to a GP
High levels of caffeine can cause anxiety, sleeplessness, agitation, a pounding or fluttering heartbeat (palpitations), diarrhoea and restlessness. If palpitations aren’t caused by a health condition, avoiding caffeine can help. See a GP if:
- You’ve had a pounding or fluttering heartbeat (palpitations) that keeps coming back, is happening more often or lasts longer than a few minutes. NHS: see a GP.
- You get palpitations and have a heart condition, or heart problems run in your family.
- Changing your sleep habits has not helped your sleep, you’ve had trouble sleeping for months, or it makes daily life hard to cope with.
Call 999 or go to A&E if palpitations do not go away, or come with chest pain, shortness of breath, feeling faint or fainting. If those symptoms have stopped, ask your GP surgery for an urgent appointment or call 111.
More on palpitations and blood tests.