Caffeine Safe Limits: Calculate Your Safe Daily Dose

Use the caffeine safe dose calculator to determine your safe daily dose of caffeine based on your body weight.

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 that 300 mg – 400 mg of caffeine can be consumed daily without any adverse effects.¹

The research behind this number uses an ‘average’ 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.

The calculator takes the medical recommendation and adjusts for your own body weight.

400 mg caffeine is equivalent to:


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.

Based on the average human body weight worldwide7,  research concludes that generally 6 mg/kg (of weight) is appropriate for those with normal sensitivity to the caffeine molecule.

Safe Caffeine Limits for Children

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

A 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 should not be a daily part of a child’s diet.

Ages 13-18

While 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 recommends that for children ages 3-18; 3 mg of caffeine per kilogram of bodyweight seems safe (but cites that data is insufficient).

Example: A 44 lb / 20 kg child could safely consume 60mg of caffeine6.

Caffeine Amount for Those with Health Concerns

Adults, as well as children, with 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.

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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 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 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
Need help with caffeine levels? Check out our list of caffeine amounts.

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?

A 2014 survey study  from The Pennsylvania State University found that on average, those ages 50-64 consume the most caffeine daily.

Surprisingly 2 to 5-year-olds consume on average 24 mg of caffeine daily.




Any advice posted on our website is for informational purposes only and is not intended to replace any medical advice. Caffeine Informer makes no representations or warranties and expressly disclaim any and all liability concerning any treatment, action by, or effect on any person following the information offered through the website. If you have specific concerns or a situation arises in which you require medical advice, you should consult with an appropriately trained and qualified medical services provider.
Written by Ted Kallmyer, last updated on November 12, 2021