Drinking more than 4-5 cups of coffee or 32-40 fl.oz. or 400 mg caffeine in a day is too much, according to the U.S. Food and Drug Administration. FDA has set a daily safe limit for adults beyond which they can experience overconsumption side effects.
The recommended daily safe limit varies for kids, pregnant females, caffeine sensitive people, insomniacs, and those with generalized anxiety disorders. If they consume coffee and caffeine beyond the prescribed limit, then it will be considered too much intake. The health risks of drinking too much coffee manifest a lot quicker in these vulnerable populations than in adults.
The side effects or health risks of drinking too much coffee i.e., more than 4-5 cups of coffee (32-40 fl.oz.) or 400 mg caffeine are anxiety and restlessness, digestive issues, insomnia, increase in heart rate, headaches, and frequent urination. FDA states that consuming 12 cups (96 fl.oz.) or 1200 mg caffeine is lethal and can even lead to death.
What is the safe amount of daily caffeine intake?
The safe amount of daily caffeine intake is 400 mg or 4-5 cups (32-40 fl.oz.) of drinking coffee for healthy adults, according to the United States Food and Drug Administration (FDA).
400 mg caffeine is not associated with any dangerous side effects in most people. However, the safe range varies for pregnant females, children i.e., both kids and teenagers, people with anxiety disorders, caffeine sensitive people, insomniacs, and people with diagnosed headaches.
Besides dosage, there are other factors like timings of caffeine consumption, form of caffeine consumption like coffee, tea, pill, or powder, plasma caffeine half life, and general health status that affects the safety of caffeine intake.
How much caffeine is in one cup of coffee?
An average 8 fluid ounce cup of drinking coffee typically contains 95 mg caffeine according to the United States Department of Agriculture (USDA).The United States Food and Drug Administration states that an 8 fl.oz. cup of brewed coffee contains 80 to 100 mg of caffeine.
However, Elizabeth Barnes, Registered Dietitian says that the amount of caffeine in a cup of drinking coffee varies and depends on the following factors.
- Types of Coffee Beans
- Type of Roasting Method
- The Amount of Ground Coffee
- Grounds Steeping Time
- The Brewing Method
- Serving Size of Cup
The amount of caffeine in one cup of 8 fluid ounces in different coffee drinks is shown in the following table.
| Coffee Drink | Caffeine(mg) in 8 fl oz | |
| 1. | Decaf Coffee | 1.8 |
| 2. | Mocha | 2.5 |
| 3. | Cafe Au Lait | 47.5 |
| 4. | Irish | 47.5 |
| 5. | Frappe | 59.3 |
| 6. | Cappuccino | 62.8 |
| 7. | Latte | 62.8 |
| 8. | Breve | 63.3 |
| 9. | Flat White | 81.6 |
| 10. | Cold Brew | 94.8 |
| 11. | Turkish Coffee | 94.8 |
| 12. | Black Coffee | 95 |
| 13. | Americano | 104.6 |
| 14. | Lungo | 125.5 |
| 15. | Vienna | 130.3 |
| 16. | Cortado | 188.3 |
| 17. | Macchiato | 376.5 |
| 18. | Espresso | 502 |
| 19. | Doppio | 1000.4 |
How many cups of coffee can you drink a day?
You can drink 4-5 cups (32-40 fl.oz.) of coffee or consume 400 mg caffeine in a day, according to the United States Food and Drug Administration (FDA). The amount of caffeine in a standard cup (8 fl.oz.) of coffee is 95 mg but it can vary in each coffee drink. Thus, make sure to drink as many cups which do not exceed the 400 mg caffeine mark.
This amount is considered safe for most healthy adults but if you experience symptoms like jitteriness, anxiety, and trouble sleeping after drinking coffee, you may be caffeine sensitive. In this case, it’s best to cut down daily coffee cups below the FDA recommendation, according to Tricia Psota, a member of the American Society for Nutrition.
According to the FDA, drinking 12 cups (96 fl.oz.) of coffee or 1200 mg caffeine in a day can cause serious symptoms like erratic heartbeat, seizures and even death.
How many ounces of coffee can you drink a day?
You can drink up to 32-40 fluid ounces of coffee a day. An 8 ounce cup of coffee contains about 95 mg caffeine, according to the FDA. FDA recommends maximum daily intake of 400 mg caffeine, so you can drink up to 32-40 fluid ounces of coffee. However, in case of caffeine sensitivity, you should cut your coffee ounces below the FDA recommendation.
What is the recommended daily intake of caffeine and coffee for adults?
The recommended daily intake of caffeine and coffee for adults is 400 mg caffeine or 4-5 cups (32-40 fl.oz.) of coffee according to the US Food and Drug Administration.
The EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) also suggests that 400 mg caffeine and 4-5 cups (32-40 fl.oz.) of coffee per day are safe for consumption in young and older adults.
This amount is safely tolerated by 90% of the general population without causing any side effects. The rest 10% are caffeine sensitive and may show adverse effects at as little as 20 mg caffeine.
What is the recommended daily intake of caffeine and coffee for pregnant women?
The recommended daily intake of caffeine and coffee for pregnant women is 200 mg caffeine or 2 cups (16 fl.oz.) of coffee according to both NHS and American College of Obstetricians and Gynecologists (ACOG). This amount is less than the FDA’s daily recommendation for non-pregnant women because caffeine in coffee can have negative effects on mothers and babies.
The graphic below shows the recommended caffeine and coffee intake for pregnant and non pregnant females.
What is the recommended daily intake of caffeine and coffee for teens?
The recommended daily intake of caffeine and coffee for teens is 100 mg caffeine or 1 cup (8 fl.oz.) of coffee, according to the American Academy of Pediatrics. Health Canada also recommends caffeine intake of 85 mg to 100 mg equivalent to 1 cup of 8 fl.oz. of coffee for adolescents aged 14-19 years.
Dietitian Susie Burrell says that adolescents under the age of 14 should avoid coffee whereas teens between 14-17 should limit caffeine intake to 100 mg caffeine.
The bar chart below recommends amount of coffee & caffeine intake for adolescents between the age of 11 to 19.
C H S Ruxton, from Nutrition Communications, Cupar, published a study in the Journal of Human Nutrition & Dietetics in 2014. She suggests caffeine consumption of 2.5 mg/kg of body weight is safe for adolescents and teens.
What is the recommended daily intake of caffeine and coffee for kids?
The recommended daily intake of caffeine and coffee for kids is zero for kids under the age of 12 years, according to The American Academy of Pediatrics.
Dr. David Buchholz, from University of Pennsylvania School of Medicine, says that caffeine and coffee can stunt growth in children. It can interfere with the bodies and minds of kids because they are smaller than adults and it takes less caffeine to cause adverse effects. A study published in Journal of Psychopharmacology revealed that drinking coffee leads to stress and anxiety in school going students.
However, Health Canada allows small amounts of caffeine and coffee daily for kids according to their ages. The following is the daily recommended intake for kids.
- Ages 4-6: 45 mg or less
- Ages 7-9: 62.5 mg or less
- Ages 10-12: 85 mg or less
The figure below illustrates the daily caffeine and coffee intake for kids according to aforementioned sources.
A study published in Journal of Human Nutrition & Dietetics Higher found no side effects of moderate caffeine intake (2.5 mg/kg of bodyweight) in kids but found anxiety and withdrawal symptoms in those consuming caffeine >5 mg/kg of bodyweight.
What is the recommended daily intake of caffeine and coffee for athletes?
The recommended daily intake of caffeine and coffee for athletes is 400 mg caffeine and 4-5 cups of coffee, according to the FDA.
The International Society of Sports Nutrition (ISSN) suggests a single dose of 3-6 mg/kg bodyweight of caffeine or 2-3 cups (16-24 fl.oz.) of coffee one hour before activity increases physical performance acutely in athletes. This single dose suggested by ISSN improves muscular endurance, muscular strength, sprinting, jumping, and throwing in athletes.
What are the side effects of too much coffee?
The acute side effects of drinking too much coffee are anxiety and restlessness, digestive issues, insomnia, increase in heart rate, headaches, and frequent urination as shown in the image below.
In severe cases, vomiting, dehydration, chest pain, seizures, and even death can occur.
Anxiety and Restlessness
Drinking more than 4-5 cups (32-40 fl.oz.) of coffee or 400 mg caffeine can cause anxiety and restlessness. 300 mg caffeine or 3 cups of coffee administered 45.36 kg per body weight increased anxiety and depression in healthy adults, according to results of a study published in the Journal of Abnormal Psychology.
Digestive Issues
Drinking more than 4-5 cups (32-40 fl.oz.) of coffee or 400 mg caffeine can cause digestive issues. A review on the effect of coffee on the digestive system states that regular coffee consumption causes gastric ulcers, gastritis, indigestion, heartburn, and gastroesophageal reflux disease (GERD) in the long term.
Insomnia
Drinking 4-5 cups (32-40 fl.oz.) of coffee daily almost doubles the risk of insomnia in both males and females, according to a study in the International Journal of Epidemiology.
A study in Nutrition also states that daily caffeine usage exposes the general population to various insomnia symptoms.
Increase in heart rate
Caffeine in coffee stimulates the sympathetic nervous system which increases heart rate. Consuming too much coffee i.e. more than 4-5 cups (32-40 fl.oz.) of coffee accelerates your heart rate beyond the normal 60-100 bpm.
Headache
Drinking 2-3 cups (16-24 fl.oz.) of coffee or 200 mg caffeine can trigger migraine headaches in migraine sufferers, according to a research in Journal ‘Nutrients’ published by Polish researchers. People with diagnosed headaches should limit their daily caffeine to 200 mg to prevent triggering of headache.
Frequent urination
Caffeine in coffee is a diuretic. Drinking too much coffee i.e. more than 4-5 cups (32-40 fl.oz.) can increase your bathroom trips beyond the normal 4-10 trips everyday.
A study in the Journal of Science and Medicine in Sport states that caffeine consumption of 300mg or more or more than 3-4 cups (24-32 fl.oz.) of coffee increases urine volume and urination in both males and females.
Severe side effects
Drinking more than 12 cups (96 fl.oz.) of coffee or 1200 mg caffeine can cause severe side effects like vomiting, dehydration, chest pain, cardiac arrhythmias, seizures, and even death, according to the FDA. Too much coffee stimulates the brain and heart causing seizures, chest pain, and cardiac arrhythmias like ventricular fibrillation which can even prove fatal, according to a study in the Journal ‘Nutrients’.
Sarah Kerrigan and Tania Lindsey from New Mexico Department of Health, Scientific Laboratory Division, Toxicology Bureau document in their study that large doses of caffeine are toxic which may present as arrhythmias, tachycardias, vomiting, convulsions, coma and death.
How much caffeine can cause a caffeine crash?
The amount of caffeine that can cause a caffeine crash depends on each individual but doses as low as 20 mg and as high as 600 mg or more can lead to a caffeine crash.
A caffeine crash is a post-coffee event which occurs after caffeine effects wear off. Since caffeine blocks adenosine, the quantity of adenosine in the brain increases beyond normal. This causes rapid binding of adenosine to its receptors causing fatigue and tiredness.
How much caffeine does it take to overdose?
The amount of caffeine it takes to overdose is 15 mg/L or higher plasma concentrations, according to Simone Cappelletti and colleagues from Sapienza University of Rome. Caffeine overdose symptoms like hypokalemia, tachycardia, and chest pain can occur after consuming 6-8 grams of caffeine as mentioned in a study published in the Journal of Toxicology: Clinical Toxicology.
For coffee, caffeine overdose symptoms like seizures and cardiac arrhythmias may present after drinking double the recommended daily intake of FDA of 4-5 cups of coffee.
What is a lethal dose of caffeine?
The lethal dose of caffeine is 1200 mg or 12 cups (96 fl.oz.) of drinking coffee consumed in a day can cause ventricular fibrillation leading to death, according to the FDA. FDA further says that consuming a teaspoon of pure powdered caffeine, equal to 28 cups of drinking coffee is fatal.
The lethal dose of caffeine is 80–100 mg/L plasma concentrations, according to Simone Cappelletti and colleagues from Sapienza University of Rome.
How much caffeine is safe for caffeine sensitive people?
The amount of caffeine which is safe for caffeine sensitive people varies for each individual but doses as low as 20-50 mg are considered safe. Most caffeine sensitive people have to eliminate caffeine intake in the form of coffee and tea completely. However, it is best that you find out the safe zone of caffeine for you by experimenting with the quantity and watching out for any adverse effects. Alternatively, you can also replace your caffeinated cup of coffee with decaf coffee.