How Much Caffeine Is in Green Tea vs. Coffee?

One cup (8 ounces) of coffee contains more than 3 times the amount of caffeine than a cup of green tea.

An average cup (8 ounces) of coffee contains more than 3 times the amount of caffeine than a cup of green tea:

• 1 cup of coffee contains about 95-165 mg of caffeine
• 1 cup of green tea contains about 25 mg of caffeine
• A cup of decaffeinated coffee contains a small level of caffeine (2 to 3 mg).
• However, just an ounce of espresso has 64 mg of caffeine.

Whatever you prefer drinking, stick to consuming less than 400 mg of caffeine total per day.

For hundreds of years, caffeine has been consumed in the form of coffee, tea, and other beverages as a stimulant that provides a boost of energy. It has been used to increase alertness, concentration, and athletic performance.

Caffeine is used in medications for:

• Headaches
• Pain relief
• Cough medications

Moderate caffeine consumption can reduce your risk of:

• Type II diabetes
• Stroke
• Obesity
• Parkinsonism
• Heart attack
• Uterine cancer
• Liver cancer
• Gout

Green tea also contains healthy substances including polyphenols, flavonoids, and antioxidants that help alleviate inflammation and prevent the formation of blood clots in arteries. This can lower the risk of diseases due to atherosclerosis, such as heart diseases and stroke.

The amino acid L-theanine in green tea works in combination with caffeine to help improve focus and alertness. This effect may make green tea a better choice for you over coffee if you need to be on your toes most of the time.

Drinking 4 cups of coffee or 400 mg of caffeine each day is generally considered safe. However, consuming more than 400 mg of caffeine per day can lead to negative side effects, including:

• Restlessness
• Irritation
• Headache
• Nervousness
• Insomnia (trouble falling asleep or staying asleep)
• Abnormal heart rhythms
• Pounding heart
• Increase in blood pressure
• Dizziness
• Anxiety
• Muscle tremors (feeling shaky)
• Frequent trips to the washroom
• Dehydration

You may be sensitive to even a small amount of caffeine. In this case, you may need to keep track of how much caffeine you consume throughout the day. 

If you are pregnant, trying to get pregnant, or breastfeeding, you need to limit your caffeine intake to less than 200 mg per day. According to a 2017 study, high caffeine consumption during pregnancy has been linked to preterm birth and low birth weight. 

If you suffer from stomach issues, such as heartburn or acid reflux, you should avoid caffeine completely or only have very small amounts.

To prevent the negative effects of caffeine, make sure you have not more than 200 mg of caffeine at a time.