Caffeine Safe Limits: Determine Your Safe Daily Dose


Caffeine Safe Dose Calculator

Your Weight

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

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 The research behind this number actually bases this on a person’s bodyweight. So if you weigh more than the average human, you can safely consume a little more but if you weigh less than the average human you should consume a little less. Our safe dose calculator above reflects this.

This is equivalent to about:


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.

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

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. We recommend using Wean Caffeine to gradually quit caffeine instead of quitting all at once which is a huge shock to your system.

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

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.


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  • Ayla77

    depends in your tolerance level. it could be anything from absoloutley nothing/ minor side effects to something really bad.

  • Ted

    Probably not a great idea. You really should have no more than 100-200 milligrams of caffeine per day at your age. Sleep is vital for proper brain development at your age, so you’re definitely hindering that process.

  • Sam Ross

    Hi I’m Sam, I take 600mg -1g of caffeine daily using no-doz 200mg tablets. I experience no adverse side effects and I sleep fine, is there anything I should be concerned about? It’s really been helping me focus lately on my studies and helps me get through the day. I’m a hypersomniac too (meaning I oversleep and am tired a lot)

  • Ted

    Hi Sam, I would advise that you try to keep your consumption at the low end of what you described. It’s already a little more than what is considered same, but if you aren’t experiencing any side effects, it seems like your body can handle it. My fear is that soon 1000 mg may not seem like enough and you’ll want to increase your dose even further. Caffeine addiction can become a slippery slope. Be mindful of this and keep your consumption in check, balanced with getting enough sleep. Also look into other more natural ways other hypersomniacs have used to feel more energized and alert. I bet their are dietary recommendations etc. that could help.

  • Ikavalios Striker

    I am Ooraka, and I will drink 1 monster a day, spreading it out, maybe 2. I am 28, and about 200lbs. However, I once had 4 monster in one day, and only felt a bit of a tingle rush, at which point I switched to pure water. I know my limit, and I drink Monster, not for the caffeine, but the taste.

  • Ayla77

    oh, okay, thank you for answering. i’ll probably cut back

  • SZ

    So, here’s a question, I’ve been trying to limit my caffeine intake to 0.5g a day or less these. Sometimes in make it, sometimes I don’t. Years and years ago I used to be in taking well over a gram a day consistently. Since then I’ve hovered around a .5g to a a gram a day for 2-3 years. Lately, I’ve been feeling weird pains or flutters in my chest randomly or occasionally after I have a high dose of caffeine. My gut tells me the pain or flutters are related to my usage over the years. My resting heart rate at my last physical was 48 with nominal bp. My doc thought she heard a mumur for a second, but couldn’t find it again
    Do you think a half gram is still safe?

  • Ted

    Most of the research and most of the health governing bodies say that 300-400 mg is considered safe. 500 mg is just a tad more than what’s recommended. I would definitely recommend trying to stay as close to 500 mg as possible. However, most of the research also says that caffeine consumption doesn’t cause heart flutters etc. but can exacerbate existing ones.

  • Joey Vengeance

    I drink on average (energy drinks and workout supplements) roughly 900mg caffeine a day. I’m aware this is bad, but how bad is it?

  • Ted

    It really depends on your health profile and sensitivity to caffeine, but here are the negatives.

  • Steven Van Hoorick

    cool story bro

  • Rosetta

    Just a basic question regarding the caffeine calculator – what size “cups” are they talking here exactly?! I got as my result “2,7 cups” being the safe amount, but there’s nothing about cup size, or amount in ml for example… (I’m in Europe so ml’s would be what I’m used to measuring in.)

  • Ted

    Hi Rosetta, it does give you a reference. Under your safe dose result it says”based a on __ floz serving. If you want to see that in mls click on the drink in question and switch the unit to mls.

  • charles

    Great site. I have a 75 year old friend who was taking Caffeine from Zija XM+. She became very confused and hallucinated. ZIJA would disclose how much caffeine is in their XM+.
    Do you know?

  • Ted

    I can look into it.

  • Rosetta

    Ok, thank you! Now I see there’s an amount in ml, but I’m sure there wasn’t any measuring unit there (ml or floz) when I first looked at the calculator, thus my message 😉

  • thexray

    hi, i visited several sites to get a good idea of how much caffeine/theobromine/mateine substances i have from 5g of pure green yerba mate leaves. it looks like it’s about 65g of caffeine for 5g tea leaves in 500ml water for 5 minutes at 80°C (1 serving is a tea bag of 3g leaves with 250 ml water for 5 minutes at 80°C with 40mg caffeine). i wonder what happens when i brew the same leaves up again. for green tea at the second brew you get 80 % of the caffeine again, and for the third brew it’s about 60 % and for the fourth still 30 %, so four brews of the same leaves would be 65 + 52 + 48 + 24 mg = 189 mg caffeine. is this probably the safest way to calculate ?
    people are putting a lot more leaves into their traditional yerba mate gourd cups than a tea bag holds and brew it up more than 4 times until the flavour is gone. i guess it’s about 20g of leaves, that would leave you with about 800 mg of caffeine per gourd cup. and then they drink a second and third one = 1600 to 2400 mg of caffeine. can this be true ?

  • Chaturbhuj Sharma

    This is Chaturbhuj Sharma
    im using a Herbalife Product Afresh energy Booster..Can you give us a idea that what quantity of Caffine is Good for health..

  • Ted

    I don’t think what you read/heard about the 2nd, 3rd, etc. brewing of tea is accurate. Caffeine is highly water soluble so I would imagine that after a 5 minute brew most of the caffeine would have been extracted. Traditional tea is usually brewed for just 3 minutes because of flavor. Longer brewing time can produce undesirable flavor qualities in the tea. I’m not sure about Yerba Mate as I don’t have experience using/brewing this type of plant.

  • thexray

    ok thanks. i just tested cold brewed green tea the last days. i wondered if any unwanted substances would be extracted by cold brewing it more than 2 hours because as you just wrote. hot brewing tea more than 3 minutes would release undesired substances, is this just flavor related for the bitter molecules or do they have a negative impact on your body or the substances released before the 3 minute mark ?

Last Modified: November 16, 2017