Caffeine Safe Limits: Calculate Your Safe Daily Dose
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 300 mg – 400 mg of caffeine can be consumed daily without any adverse effects.¹ The research behind this number actually bases this on a person’s body weight. 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:
- 5.2 Shots of espresso
- Two 5 Hour Energy Shots
- 1 Starbucks Venti brewed coffee
- 2.5 16 fl oz Monster Energy Drinks
- 5 8 fl oz Red Bulls
- 11.7 12 fl oz Cokes
A large review by European Food Safety Authority concluded that a daily safe dose of 400 mg is safe for adults and single doses of 200 mg at one time are fine for those engaging in exercise directly after the dose.
Safe Caffeine 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 45 mg per day¹ is recognized as a safe amount, but caffeine shouldn’t be a daily part of a child’s diet.
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 100 mg 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; 3 mg of caffeine per kilogram of body weight seems safe. i.e. a 20kg child could safely consume 60mg of caffeine6.
Caffeine Amount 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.
1. Download our book Awake (it's free).
2. Do the Overcoming Caffeine Withdrawal course at Udemy.
3. Use the Wean Caffeine supplement (something we helped get to market). It helps you avoid the painful withdrawal symptoms that often come when quitting caffeine abruptly.
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 200 mg 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 200 mg 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, most experts agree that consuming 200 mg or less of caffeine a day equates to very little risk for the developing fetus and/or nursing infant.
200 mg 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 (100 mg-120 mg) in the morning and still fail to get to sleep that evening. This is well after the caffeine’s effects should have worn off such as it does for “normal” caffeine metabolizers.
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 50 mg 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
A General Guide to Caffeine Consumption Only
Our caffeine safe limit recommendations listed above are based on what the latest research tells us and should be used as a general guide, not “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 like any other drug and used with caution until a person understands how the substance 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 24 mg of caffeine daily. This means that many would consume much more.
We populated their data into the graph below.
- 1. Heckman, M. A., Weil, J. and De Mejia, E. G. (2010), Caffeine (1, 3, 7-trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters. Journal of Food Science, 75: R77–R87. doi: 10.1111/j.1750-3841.2010.01561.x Link
- 2. http://www.psychologytoday.com/blog/teen-angst/201305/over-caffeinated-teens
- 3. https://www.mja.com.au/journal/2001/174/10/caffeine-induced-cardiac-arrhythmia-unrecognised-danger-healthfood-products
- 4. http://care.diabetesjournals.org/content/27/8/2047.full
- 5. Leading image credit.
- 6. Seifert SM, Schaechter JL, Hershorin ER and Lipshultz SE, 2011. Health effects of energy drinks on children, adolescents, and young adults. Pediatrics, 127, 511-528. PDF
- 7. Average weight of human adult is 62kg Walpole, S. C., Prieto-Merino, D., Edwards, P., Cleland, J., Stevens, G., & Roberts, I. (2012). The weight of nations: an estimation of adult human biomass. BMC Public Health, 12(1), 439. LInk
- EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2015. Scientific Opinion on the safety of caffeine. EFSA Journal 2015;volume(issue): 112 pp. doi:10.2903/j.efsa.2015. Link