TL;DR: The NHS puts a cup of instant coffee at about 100mg of caffeine, and says filter coffee and coffee-shop coffee can contain more. A single espresso can be anything from about 50mg to over 300mg, depending on who made it. For healthy adults, Europe's food safety authority says up to 400mg a day from all sources raises no safety concerns, and the NHS advice in pregnancy is no more than 200mg a day. The biggest things that change the number: how much coffee goes in, which species of bean it is, and how you brew it.
Brewing at home is the easiest way to know what's in your cup. Every coffee we roast is 100% Arabica, and our Highwire blend is built to taste great as an espresso and as a filter. For the afternoon cup, there's Mellow Moon, our Colombian decaf.
A team at the University of Glasgow bought espressos from 20 coffee shops and measured the caffeine in each one. The lowest had 51mg. The highest had 322mg. Same drink, same name on the menu, more than six times the caffeine (Crozier et al., 2012).
So the honest answer to "how much caffeine is in a cup of coffee" is: it depends, a lot. As roasters, we can show you exactly where the caffeine in your cup comes from, and which of those levers you control at home.
How much caffeine is in a cup of coffee, drink by drink?
These are the most reliable figures we could find, with tea and cola for comparison:
| Drink | Typical caffeine | Source |
|---|---|---|
| Cup of instant coffee | about 100mg | NHS |
| Filter or coffee-shop coffee | can be more than instant | NHS |
| Regular brewed coffee, 12 fl oz (about 355ml) | 113mg to 247mg | US FDA |
| Single espresso, bought in a coffee shop | 51mg to 322mg | Crozier et al. 2012 (20 Glasgow coffee shops) |
| Decaf coffee, 8 fl oz (about 240ml) | 2mg to 15mg | US FDA |
| Cup of black or green tea | about 75mg | NHS |
| Can of cola | about 40mg | NHS |
Two things jump out. First, the ranges are wide, so one exact number for "a cup of coffee" is only ever an average. Second, an espresso isn't automatically the strong one. It's small, but a big mug of filter can easily carry more.
Why does the caffeine in coffee vary so much?
Four things decide what ends up in your mug:
- The dose. More ground coffee in, more caffeine out. This is the big one, and it's the one you control.
- The species. Robusta beans carry roughly twice the caffeine of Arabica (more on that below).
- The brew. How long the water spends with the coffee, how fine the grind is and how hot the water is all change how much caffeine gets pulled out.
- The cup size. A 12oz takeaway and a small home mug aren't the same "cup", even with identical coffee in them.
Roast level gets a lot of blame here too. It matters far less than people think.
Does Arabica or Robusta coffee have more caffeine?
Robusta, by a distance. Measurements vary by farm and harvest, but Robusta beans typically come out at around twice the caffeine of Arabica by weight. One study of Arabica and Robusta beans from Rinjani, Indonesia, found Arabica averaging 1.09% caffeine and Robusta 2.09% (FAO AGRIS record).
Robusta has its place. Every coffee has a home. But every coffee we roast at Chipp is 100% Arabica, from traceable sources. We pick coffees for flavour: the chocolate, caramel and spice in Highwire, or the sweet, balanced cup that is Mellow Moon. If you're drinking our coffee, you're drinking Arabica, which sits at the gentler end of the caffeine scale.
Does dark roast coffee have more caffeine than light roast?
Not reliably, either way. This is one of coffee's longest-running arguments, and a 2024 study in Scientific Reports tested it properly with filter brews. The answer was messier than either side wanted: caffeine in the cup peaked in medium roasts, and how well the coffee extracted mattered more than the roast level alone (Lindsey et al., 2024).
So pick your roast for how it tastes. If you love bright, fruity light roasts, our guide to the perfect V60 brew temperature for light roasts will get more out of them. If you run a bean-to-cup machine, our bean-to-cup guide covers why medium roasts are the safe bet.
Which brewing method has the most caffeine?
It comes down to how much coffee you use and how much of the cup you drink:
- Espresso: the most concentrated per millilitre, but a single shot is small. As the Glasgow study showed, the total depends heavily on the dose the barista uses.
- Milk drinks (flat white, latte, cortado): carry exactly the caffeine of the espresso shots inside them. The milk changes the taste and the size; the caffeine stays put.
- Americano: the same as the shots in it. Adding hot water makes it longer and leaves the caffeine where it was.
- Filter and cafetière: a bigger drink with more coffee in it overall, so often more caffeine per mug than a single espresso. If your French press tastes muddy or bitter, that's down to extraction, and our guide sorts it.
- Cold brew: a 2017 study found coarse-ground cold brew samples had more caffeine than their hot-brewed equivalents (Fuller and Rao, 2017). Many recipes also use a lot of coffee and make a concentrate to dilute, so how much water you add makes a big difference.
How much caffeine is too much?
For healthy adults, the European Food Safety Authority says habitual intakes of up to 400mg a day don't raise safety concerns, and single doses of up to 200mg are fine too (EFSA, 2015). That's all caffeine, from coffee, tea, cola, energy drinks and chocolate.
If you're pregnant, the NHS advice is no more than 200mg a day (NHS). At the NHS figure of about 100mg for a cup of instant, that's two cups. One strong espresso from the Glasgow study would have gone over it on its own.
Everyone's different, so if you're unsure what's right for you, have a chat with your GP, midwife or pharmacist.
How much caffeine is in decaf coffee?
Some, but not much. The FDA puts a typical 8 fl oz cup of decaf at 2mg to 15mg (FDA), compared with 113mg to 247mg for a 12 fl oz regular brew.
Our decaf, Mellow Moon, comes from smallholders in Huila and Tolima in Colombia. It's decaffeinated with the sugarcane process: the beans are steamed, then soaked in ethyl acetate, a compound found naturally in ripe bananas and beer, until 97% of the caffeine is gone. What's left is a sweet, balanced coffee with chocolate and caramel notes, and it works as espresso, filter, AeroPress or in a moka pot. For more on why decaf is having a moment, read Decaf Coffee on the Rise.
How can you control the caffeine in your coffee at home?
This is where brewing at home wins. You know exactly what's going in:
- Weigh your coffee. A cheap set of kitchen scales tells you more about your caffeine than any chart. Keep the dose the same and your cup stays consistent day to day.
- Swap the later cups. Keep your favourite coffee for the morning and switch the afternoon one to decaf.
- Make your own half-caff. Mix regular and decaf beans 50/50 before grinding. Highwire and Mellow Moon are both chocolatey, so they get on reyt well together.
- Watch the mug size. If the mug's got bigger over the years, so has your caffeine.
- Fewer cups, better coffee. If you're keeping count, make every cup one you look forward to.
FAQs
How much caffeine is in a shot of espresso?
It varies more than most people expect. When Glasgow researchers measured espressos from 20 coffee shops, single servings ranged from 51mg to 322mg. At home, the dose of coffee you put in the basket is the biggest factor.
Does adding milk reduce the caffeine in coffee?
No. Milk makes the drink bigger and softer tasting, but the caffeine is whatever was in the espresso or coffee to start with.
Does dark roast have more caffeine than light roast?
There's no simple rule. A 2024 study found caffeine in filter coffee peaked in medium roasts, and that extraction mattered more than roast level on its own.
Is decaf coffee caffeine-free?
Not completely. A typical cup of decaf has 2mg to 15mg of caffeine, according to the FDA. Our Mellow Moon decaf has 97% of its caffeine removed.
How many cups of coffee is 400mg of caffeine?
At the NHS figure of about 100mg for a cup of instant, roughly four. Filter and coffee-shop coffee can contain more, so the real number for your cups may be lower. Remember tea, cola and chocolate count too.
Is cold brew stronger than hot coffee?
Often, yes, but mostly because of the recipe. Cold brew is usually made with a lot of coffee, sometimes as a concentrate, and one study found coarse-ground cold brew pulled out more caffeine than hot brewing.
Make every cup count
Those Glasgow espressos swung from 51mg to 322mg because the dose changed from shop to shop. In your kitchen, you set the dose. Pick one, pick a coffee you love, and switch to decaf when the day's winding down.
If you want something new to look forward to every month, Roasters Choice sends you a coffee our head roaster has picked, often new crop or kept for subscribers. Choose the size and grind, get it every 7, 14 or 30 days, and skip, pause or cancel any time. We're rated 4.9 on Trustpilot from 336 reviews, and if you don't love it, we'll make it right.
About the author: Zach Chipp founded Chipp Coffee Co. in Leeds and has been roasting here since 2016, after starting out as a consultant to other coffee roasters. Our head roaster, Mathew, is a certified Q grader, the coffee industry's qualification for grading and scoring coffee. Between the team, we've got over 20 years of experience in the coffee industry.
Sources
- NHS, Foods to avoid in pregnancy (caffeine section): https://www.nhs.uk/pregnancy/keeping-well/foods-to-avoid/
- European Food Safety Authority (2015), Scientific Opinion on the safety of caffeine, EFSA Journal 13(5):4102: https://doi.org/10.2903/j.efsa.2015.4102
- US Food and Drug Administration, Spilling the Beans: How Much Caffeine Is Too Much?: https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much
- Crozier, Stalmach, Lean and Crozier (2012), Espresso coffees, caffeine and chlorogenic acid intake: potential health implications, Food & Function 3:30-33: https://eprints.gla.ac.uk/58252/
- Lindsey et al. (2024), Caffeine content in filter coffee brews as a function of degree of roast and extraction yield, Scientific Reports 14:29126: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11586412/
- Fuller and Rao (2017), The effect of time, roasting temperature, and grind size on caffeine and chlorogenic acid concentrations in cold brew coffee, Scientific Reports 7:17979: https://pmc.ncbi.nlm.nih.gov/articles/PMC5740146/
- The chemical characteristics of Arabica and Robusta green coffee beans from Geopark Rinjani, Indonesia (FAO AGRIS record): https://agris.fao.org/search/en/records/6759c3d50ce2cede71cb69bf
- Chipp Coffee Co. product pages: Highwire, Mellow Moon, Roasters Choice
