How Much Caffeine Should You Have Per Day?

How much caffeine a day is too much? Because no-one likes having the sweats and the shakesPhoto by Kate Anglestein

How Much Caffeine Should You Have Per Day?

by Kat Naoum |
Published on

Did you know that there’s such a thing as too much caffeine? Looks at sixth cup of coffee and gulps. So how much caffeine a day should we be having? Check out our ultimate guide to the caffeine amounts in all of your fave beverages so that you can calculate how much caffeine you’re getting a day and whether maybe you should lay off just a tad.

How Much Caffeine A Day Should We Have?


Many of us would like the answer to this question to be “unlimited” but, unfortunately, this is not to be. The recommended daily allowance for caffeine is 300-400 milligrams per day. That’s roughly four cups of coffee, 10 cans of coke, or two energy drinks like Monster or Red Bull. Some doctors even suggest only 100-200mg per day but caffeine affects people differently according to their size gender and caffeine tolerance. Experts however seem to agree that 600 mg of caffeine (4-7 coffees a day) or more is way too much. for caffeine is 300-400 milligrams per day. Before we go into the exact amounts of caffeine in coffee, tea, hot cocoa and other caffeinated beverages, there’s a few things you need to know about caffeine first.

How Does Caffeine Work?

Caffeine is similar to a chemical we all already have in our bodies, called adenosine. In the brain, adenosine binds toadenosine [receptors in the brain and can act as a central nervous system depressant {href='' target='_blank' rel='noopener noreferrer'}inhibitory neurotransmitter).

Adenosine makes us sleepy and perhaps a bit lethargic because it slows down nerve activity, and our adenosine levels increase throughout the day, hence why we get more and more tired as the day goes by.

Caffeine does the exact same thing as adenosine in that it binds to the adenosine receptors. However, in stark contrast to adenosine, it doesn’t make us sleepy or slow us down. It utilises all the receptors that are usually bound to adenosine so that the cells can no longer sense adenosine.

And that, ladies and gents, it why caffeine keeps us wide awake and ready for action.

How Does Caffeine Affect The Body?

Once caffeine is ingested into our systems, it takes around 45 minutes to be fully absorbed into the blood stream but only takes up to 15 minutes to start working.

Apart from waking us up and helping us function on a daily basis, caffeine has many effects on the body such as increasing the acid release of the stomach which can sometimes lead to stomach ache or heartburn. It could also aid weight loss. Caffeine, if you have’t noticed, is also a diuretic which makes you pee more than you would normally as it makes your body lose more fluid. In this way, caffeinated beverages don’t count towards your 8 glasses of water a day, so if you’re a big tea or coffee person, make sure you also drink plenty of water so that you don’t get dehydrated.

Caffeine can also relieve headaches because it blocks adenosine's ability to open up the brain's blood vessels, causing them to constrict, so in the case of some headaches, the narrowing effect of caffeine on the blood vessels can ease your ouchy head.

It also, through a series of peculiar events, produces adrenaline, which has the following effects on the body:

▪Dilated pupils

▪Opened breathing tubes

Increased heartbeat

▪Increased blood pressure

▪Slower stomach blood flow

▪More energy due to sugar released from the liver into bloodstream

▪Tightened muscles.

What Are The Effects Of Too Much Caffeine?

It is possible to overdose on Caffeine. If you have too much caffeine, your body could have any one (or all; ouch) of the following symptoms:





•Upset tummy


•Muscle tremors.

So, in order for you to get a rough idea of how much caffeine you should be having a day to avoid these symptoms, we break down the approximate amounts of caffeine in your favourite caffeinated beverages via Caffeine Informer.

How Much Caffeine In Coffee?

Not every cup of coffee has the same level of caffeine in it and there are many things that can factor in the varying caffeine levels of each drink. For example, the longer you brew coffee, the higher the level of caffeine it will have, so french press coffee which you’re supposed to leave to brew for five or so minutes, has a higher level of caffeine than, let’s say, a ristretto espresso (the teeny tiny one) which comes out quite quickly. Same applies to cold coffees too.

Another factor to be aware of is the natural caffeine quantity in each different type of coffee bean or tea leaf (i.e the Robusta coffee bean which is used mainly for instant coffees has around twice as much caffeine as the Arabica coffee bean which is often used in good quality coffee houses for drip-coffees).

Taking all this this into consideration, the question ‘how much caffeine is in a cup of coffee’ is roughly the same as asking how long is a piece of string. The only way to really be able to tell precisely how much caffeine is in your drink is to send it off to a lab and ain’t nobody got time for that. But don’t worry, we do have approximate numbers for ya.

The average cup of coffee contains 100 milligrams of caffeine. If coffee is your drink, then stick to 4-5 cups a day to avoid aforementioned side-effects.

How Much Caffeine In Espresso?

An espresso has around 50-70 mg of caffeine per shot, so a double espresso has around 150mg. Best to stick to up to either 4 to 5 singles or 2 doubles per day.

How Much Caffeine In Instant Coffee?

A cup of instant coffee (as long we’re talking one teaspoon full of granules) has approximately 60 mg of caffeine in it, which means that you can have up to 6 a day if you must.

How Much Caffeine In Decaf Coffee?

No, this is not a trick question. Even decaf coffee has a bit of caffeine in it, albeit nowhere near as much as fully caffeinated coffee. A cup of decaf coffee has 30 mg in it so you can have around 10-13 cups. Not bad, not bad.

How Much Caffeine In Tea?

As a nation of tea-drinkers, this is something we should know about. Just as with coffee, all teas have different levels of caffeine in them, and broken tea leaves tend to have more caffeine than whole leaves. Our favourite teabags such as PG Tips and Tetley have broken tea leaves which means they have higher caffeine levels. There is approximately 30 mg of caffeine in a cuppa (with one teabag) but here are some other tea caffeine numbers if steeped for 3 minutes: -

Black Tea - between 40 and 120 mg

Assam Black Tea - 86 mg

White Tea - 75 mg

Darjeeling - 56 mg

Indian Green Tea - 59 mg

Kenyan Green Tea - 58 mg

Ceylon Black Tea - 58 mg

3-4 cups of tea a day should be the limit.

How Much Caffeine In Decaf Tea?

Decaf black tea usually contains about 2-10 mg of caffeine. So you can pretty much knock yourself out.

How Much Caffeine In Hot Chocolate?

A hot chocolate has a tiny 5 mg of caffeine in it, so it’s no wonder that especially if topped up with milk, it’s not going to do much in keeping you awake. Have as many as you like, but no more than 80 a day, OK?

How Much Caffeine In Coke?

A hot chocolate has a tiny 5 mg of caffeine in it, so it’s no wonder that especially if topped up with milk, it’s not going to do much in keeping you awake. Have as many as you like, but no more than 80 a day, OK?

How Much Caffeine In Diet Coke?

A can of Diet Coke surprisingly has more caffeine in it than normal Coke. At 46 mg, this means that with 8 cans, you’ve reached the limit.

How Much Caffeine In Coke Zero?

A can of Coke Zero has 34 mg of caffeine in it so again, no more than 11 a day.

How Much Caffeine In Red Bull?


It’s no surprise that a Red Bull has a shit load of caffeine in it. At 80 mg per can, it’s not a good idea to have more than 3-4 a day.

How Much Caffeine In Monster?

One can of Monster Energy Drink has 160mg of caffeine in it and the Mega Monster has a whopping 240 mg! One to two cans should do you for the day… or week!

Drink with caution. Or ignore everything you just read and do what you were doing anyway.

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This article originally appeared on The Debrief.

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