Caffeine Safe Limits: Determine Your Safe Daily Dose

how-much-caffeine

A safe caffeine limit is the amount of caffeine a person can consume without experiencing any negative caffeine overdose symptoms.

It’s difficult to assign an exact amount for everyone because people can have different sensitivities or reactions to caffeine based on age, medical history, and tolerance.

However, there is enough research available to make a recommendation based on an individual’s weight.

Caffeine Amounts for Healthy Adults

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For healthy adults with no medical issues, it is generally agreed upon that 300mg-400mg of caffeine can be consumed daily without any adverse effects.¹

This is equivalent to about:

adult-caffeine-safe-dose-comparison

A large review by European Food Safety Authority concluded that a daily safe dose of 400mg is safe for adults and single doses of 200mg at one time are fine for those engaging in exercise directly after the dose.

Based on on average body weights worldwide7, we conclude that 6mg/kg (of weight) is appropriate. Calculate your daily maximum for any drink here.

Safe Limits for Children

Because children’s brains are continuing to develop and their bodies are still growing, limited caffeine is recommended.

A recent study from The University Children’s Hospital in Zurich showed the importance of sleep for a child’s developing brain. Caffeine can interfere with sleep, therefore, possibly hindering proper brain development.

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Ages 12 and Under

Caffeine isn’t recommended for children under 12. Occasionally, some doctors may recommend caffeine for children diagnosed with ADHD, but generally, there really is no reason for children under 12 to consume caffeine.

For children 4 or older an occasional caffeinated soda or chocolate treat will likely pose no concern and around 45mg per day¹ is recognized as a safe amount, but caffeine shouldn’t be a daily part of a child’s diet.

Ages 13-18

While greatly limiting caffeine to this age group would be ideal, because of the increasing demands placed on teenagers in regards to school, sports, and even work; caffeine consumption is becoming more common with this age group.

Developing teens should have no more than 100mg of caffeine daily² due to the importance of sleep, brain development, inexperience with caffeine, and possibly unknown medical conditions.

This is equivalent to about:

  • 1.3 Shots of espresso
  • 1.25 8 fl.oz. Red Bulls
  • .5 of a 5 Hour Energy Shot
  • .6 of a 16 fl.oz. can of Monster Energy Drink
  • .2 of a Starbucks Venti brewed coffee
  • 3 12 fl.oz. Cokes
caffeine-safe-limits-teens-comparison

The European Food Safety Authority also stated in their draft report that for children ages 3-18; 3mg of caffeine per kilogram of body weight seems safe. i.e. a 20kg child could safely consume 60mg of caffeine6.

Caffeine for Those with Health Concerns

Adults as well as children with either diagnosed or undiagnosed medical conditions can have adverse health implications with even small amounts of caffeine. For those with certain health conditions, giving up caffeine may be recommended. Here are some conditions that usually warrant quitting caffeine or caution consuming the drug.

Heart Conditions

Because caffeine is a stimulant, it increases heart rate as well as blood pressure. Therefore, those with heart arrhythmias³, murmurs, and hypertension should limit their caffeine intake.

It’s important to note that caffeine hasn’t been proven to cause arrhythmia, heart disease or other heart-related problems.¹

Those with pre-existing arrhythmias, murmurs, and hypertension should limit caffeine to no more than 200mg daily and are advised to consult their physician before consuming caffeine.

Type 2 Diabetes

The majority of the research shows that caffeine doesn’t increase the risk of someone developing type 2 diabetes, but actually decreases risk.¹

However, those already diagnosed with type 2 diabetes should limit caffeine consumption because it can impair glucose metabolism in diabetics.4

Those with type 2 diabetes should restrict their consumption to around 200mg daily or follow their doctor’s instructions concerning caffeine intake.

Pregnant or Nursing Women

We have covered pregnancy and caffeine extensively in our article located here.

In summary, we concluded that mothers consuming 200mg of caffeine or less a day results in very little risk for the developing fetus and nursing infant.

200mg of caffeine is equivalent to about:

  • 2.6 shots of espresso
  • 2.5 8 fl.oz. Red Bulls
  • One 5 Hour Energy Shot
  • .5 of a Starbucks Venti Brewed Coffee
  • 1.25 16 fl.oz. Monster energy drinks
  • 6 12 fl.oz. Cokes
caffeine-safe-doses-health-conditions

Those Ultra-Sensitive to Caffeine

For those ultra-sensitive to caffeine it is hard to determine an exact caffeine safe limit. Some people can have one cup of coffee (100mg-120mg) in the morning and still fail to get to sleep that evening. This is well after the caffeine’s effects should have worn off as it does for “normal” caffeine consumers.

If the ultra-sensitive choose to consume caffeine they should do so in small amounts until they find the amount that works, but doesn’t cause unwanted side-effects.

We suggest that these people start with 50mg of caffeine daily and then slightly increase or decrease their consumption from there.

This is equivalent to about:

  • 1.5 12 fl.oz. Cokes
  • 1 4 fl.oz. brewed coffee. (not Starbucks)
  • 1 8 fl.oz. strong black tea
Need help with caffeine levels? Check out our huge list of caffeine amounts.

A General Guide to Caffeine Consumption Only

Our caffeine safe limit amounts listed above are based on what the latest research tells us and should be used as a general guide, not the “gospel’.

There are just too many variations in the human population to determine a safe limit for caffeine use in ALL people.

Caffeine should be treated as any other drug and used with caution until a person understands how it interacts with his/her particular genetic make-up and health profile.

It’s also important to understand that a person’s safe limit of caffeine can change over time as a person’s health evolves over his/her lifetime.

How Much Caffeine Are Americans Consuming?

The Department of Nutritional Sciences from The Pennsylvania State University recently conducted a survey study and found that on average, those ages 50-64 consume the most caffeine daily.

The most shocking part of their data is the fact that 2 to 5-year-olds consume on average 24mg of caffeine daily. This means that many would consume much more.

We populated their data into the graph below.

usa-caffeine-consumption

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  • Danielle Robertson

    What a fantastic breakdown! This systematic advice is incredibly helpful, especially since so many forget the dose makes the difference between hazardous and safe. The only thing I would add is that “Consumption Specifics” such as dehydration, time since last meal and speed of consumption also impact the effects of caffeine. These Consumption Specifics are discussed in the book Are You a Monster or a Rock Star: A Guide to Energy Drinks

  • Ted

    Great point Danielle, 400mg all at once is a lot different than 400mg over the course of 6-12 hours. Which makes the Starbucks Venti a bit alarming if one were to drink it rather fast.

  • Alas, one built-in safety feature of coffee: it’s harder to chug a hot beverage than a cold one (but still possible and thus, still hazardous in excess).

  • Ray

    That’s fucked up! Main ingredient in red bull is not caffeine, it’s taurine. Can’t compare apples to oranges, this is NOT safe. 5 red bulls = heart attack lol

  • Ted

    We are only comparing each beverage as it relates to caffeine.

  • Katie

    I drank 12 20 oz Mountain Dew Code Reds once and proceeded to become rapidly sick. I can handle caffeine about as well as the average person and my cardiologist says my heart condition isn’t bad enough to worry about caffeine. But 91 mg x 12 bottles = 1092 mg of pure illness by caffeine. The most I ever drink now is 2 at a time and twice daily when I have to be awake for a few days.

  • Ted

    So glad your doctor caught that and that you are following his/her advice.

  • Bob Huddleston

    How about the research on the effects of caffeine on the immune system? …
    Science: …Weakening the Physiological Immunosuppressive
    Mechanism
    Example: http://www.jimmunol.org/content/179/11/7431.long

    Popular Press: http://www.livestrong.com/article/507741-how-caffeine-affects-the-immune-system/

  • Ted

    Thanks for pointing that out. Interesting that a high dose of caffeine actually prevented liver damage in mice.

  • Rebecca

    I am not surprised by the starbucks results. I average about 200mg of caffeine a day, but one day I had starbucks and it sent me overboard and I was literally crying because I couldn’t handle it

  • Ted

    Yes, you are not alone. Many have been surprised by Starbucks since they assumed it was just like their home brew or other restaurants.

  • Taurine is an amino acid that your body makes on its own. it’s not dangerous for you at the levels it’s found in energy drinks.

  • lkfman

    Thanks for a terrific site! Most of my friends call me a freak of nature and say I should donate my body to science. On a normal workday, I will drink 1 can of Cocaine a day, 3 on Friday and usually 5 a day on weekends. 2 when I first get up and the last before I go to sleep. At my 30 year high school reunion, it was 7 cans and a Wired 505 in a 6 hour span and sound asleep within 20 minutes of returning home. It seems pretty weird that I seem to have no adverse reaction, my bp and pulse were 127/69 and 49 after my 4th can today. Any advice, suggestions or words of wisdom???

  • Ted

    You’re welcome! Glad you like it. I’ve known other people like you who have the body chemistry which allows them to consume large amounts of caffeine with little effect. And, who can have coffee right before bed time and sleep like a baby. In your case I would be more concerned with the amount of sugar you are consuming some days a s opposed to the caffeine. 7 Wired’s is 350 grams of sugar unless you were consuming sugar free ones.

  • lkfman

    Actually it was 7 of the Cocaine and 1 Wired 505. Looking at the can now, Cocaine, 7 cans equaled 105 grams. I did enjoy the Wired though except the 24oz size can could get to be a little too much to drink occasionally. I really think my job as a UPS driver helps to keep thing in check.

  • MrJensenn

    Haha, I am also one of these persons who can drink or consume caffeine from pills, coffee, energy drinks and what not and still be able to sleep like a baby. That is when I have consumes less than 500mg.

    I can consume huge amounts and feel no energy etc, but that is probably because I have been eating a lot of caffeine pills lately for exams and such.
    (One normal example is consuming 400-600mg caffine and don’t feeling it. That is too bad. I had a misunderstanding that 3.6g of caffeine would kill you, good I had your site to correct me. Now I can consume 14.4g’s before I am getting put down :p)

  • MrJensenn

    You are the second person I am having this discussion with… Where are your sources?

    I have consumes lots of taurine lately and I am still beating around, not that I am a prime example, but I feel that I have some kind of experience with it.

  • Señor Wibbington

    (I know I shouldn’t do this) but I can drink 4 monsters in a course of 2 hours and still be fine and someone died from chugging two in like a minute so I agree with you Danielle

  • Señor Wubbington

    About speed of consumption

  • Thank you, Senior. Wow, 4 Monsters in 2 hours is a lot! That’s what, 4×160, so 640mg! I know the speed of caffeine metabolism is affected by a few factors including age and whether or not you smoke or are on The Pill. Right now I’m reviewing research on liver enzymes to better understand how some people like you and one of my dear friends can handle so much caffeine in a day. Senior, have you been consuming caffeine for many years?

Last Modified: March 31, 2016

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