A Complete Guide to How Much Caffeine Is in Green Tea Per Day

December 21, 2025 •

3 min read

An average 8-ounce cup of green tea contains between 30 and 50 milligrams of caffeine. Understanding how much caffeine is in green tea per day is vital for managing energy levels, maximizing its benefits, and avoiding potential side effects associated with excessive intake.

Quick Summary

The amount of caffeine in green tea varies by type and brewing method, typically falling below coffee's level. For most healthy adults, consuming up to 400mg daily is safe, allowing for several cups of green tea. The presence of L-theanine provides a smoother energy boost than coffee.

Key Points

Standard caffeine content: A typical 8-ounce cup of green tea contains 30–50 milligrams of caffeine.
Matcha has more caffeine: Because you consume the entire ground leaf, Matcha has a higher caffeine content per serving than brewed green tea.
Many factors affect caffeine levels: Brewing time, water temperature, tea variety, and leaf age all influence the final caffeine amount.
Healthy adults can consume up to 400mg daily: The FDA considers up to 400mg of caffeine per day safe for most healthy adults, which allows for several cups of green tea.
L-theanine provides 'calm alertness': An amino acid in green tea, L-theanine, works with caffeine to promote a state of relaxed focus, reducing jitters often associated with coffee.
Brewing longer or with hotter water increases caffeine: For less caffeine, use cooler water and steep for a shorter duration.

Green tea is a popular beverage cherished worldwide for its delicate flavor and numerous health-promoting compounds. Derived from the leaves of the Camellia sinensis plant, it is praised for its antioxidant content and the unique sense of 'calm alertness' it provides. However, for those monitoring their stimulant consumption, a key question remains: how much caffeine is actually in your daily cup?

The Average Caffeine Content in a Cup of Green Tea

While specific caffeine levels can vary widely, a standard 8-ounce (240 ml) cup of brewed green tea typically contains between 30 and 50 milligrams of caffeine. This is significantly lower than a similar-sized cup of brewed coffee, which can contain anywhere from 95 to 200 mg.

Factors That Influence Caffeine Levels

Several factors can cause the caffeine content of your green tea to fluctuate:

Tea Variety and Leaf Maturity: Younger leaves and buds, like those in Gyokuro and Matcha, usually have more caffeine. Older leaves (Bancha) have less. Shade-grown teas (Matcha, Gyokuro) also tend to have higher caffeine.
Brewing Temperature: Hotter water extracts more caffeine. Green tea brewed with cooler water, as is typical, has less caffeine than black tea brewed at higher temperatures.
Steeping Time: Longer steeping releases more caffeine. Short steeps yield less caffeine, while longer steeps result in more.
Form of Tea: Tea bags often have small leaf pieces (fannings) that release caffeine quickly. Powdered teas like Matcha include the whole leaf, leading to higher caffeine per serving than brewed tea.
Leaf-to-Water Ratio: More tea leaves per volume of water means a higher caffeine concentration.

Comparison: Green Tea vs. Other Beverages

Understanding how green tea compares to other common beverages can help put its caffeine content into perspective. All values are approximate for an 8-ounce serving unless otherwise noted.


Beverage	Average Caffeine Content	Notes
Green Tea	30–50 mg	Includes standard loose leaf and tea bags.
Matcha (Green Tea)	30–60 mg	Can be higher, up to 70 mg per serving, due to consuming the whole leaf.
Hojicha (Roasted Green Tea)	10–20 mg	Lower caffeine due to the roasting process.
Brewed Coffee	95–200 mg	Significantly more caffeine than most green teas.
Black Tea	25–110 mg	Often has more caffeine than green tea, depending on preparation.
Energy Drinks	72–80+ mg	Often contain high levels of added sugar or artificial additives.
Herbal Tea	0 mg	Naturally caffeine-free and made from herbs, not Camellia sinensis.

How Many Cups of Green Tea Per Day is Safe?

The U.S. Food and Drug Administration (FDA) and other health bodies state that up to 400 mg of caffeine per day is considered safe for most healthy adults. For the average cup of green tea (30–50 mg), this would allow for up to 8 cups a day, assuming no other caffeine sources. However, personal sensitivity and the type of tea play a significant role. Some studies suggest 3–5 cups daily is optimal to maximize health benefits, while very high doses can lead to side effects.

Special Considerations

Certain individuals should limit their caffeine intake more strictly:

Pregnant or breastfeeding women: Many experts recommend limiting caffeine to 200–300 mg per day.
Individuals sensitive to caffeine: Those who experience anxiety, jitters, or increased heart rate should consume less.
People with certain health conditions: Individuals with anxiety disorders, heart conditions, or high blood pressure should consult a doctor regarding caffeine intake.

The Unique Balancing Act with L-Theanine

Green tea's unique effect compared to coffee is partly due to the amino acid L-theanine. L-theanine works with caffeine to promote relaxation and reduce potential jitters or anxiety. This combination results in calm alertness, improved focus, and a smoother, sustained energy boost.

Strategies for Controlling Your Caffeine Intake

If you are sensitive to caffeine or wish to reduce intake, you can still enjoy green tea. Here are strategies:

Opt for low-caffeine varieties: Choose teas like Hojicha or Bancha.
Adjust brewing: Use cooler water and shorten steeping time.
Try decaf green tea: Look for quality decaf options with less than 12 mg per serving.
Monitor your body: Pay attention to how different amounts affect you; everyone's tolerance varies.

Conclusion: Moderation is Key

For most people, the caffeine in green tea per day is manageable and can be healthy. Its moderate levels, combined with L-theanine and antioxidants, offer a balanced energy boost without the crash of coffee. Understand the factors influencing caffeine, listen to your body, and adjust brewing or tea choice to suit your needs. Consult a healthcare provider if you have health concerns about caffeine or green tea.

Frequently Asked Questions

Green tea has significantly less caffeine than coffee. A typical 8-ounce cup of green tea contains 30–50mg of caffeine, while the same amount of brewed coffee contains 95–200mg.

Due to consuming the entire ground leaf, a single serving of Matcha typically contains more caffeine than brewed green tea, with concentrations ranging from 30–60 mg or higher, depending on the preparation.

For most people, moderate consumption is safe. However, excessive amounts (over 8 cups or 400mg of caffeine daily) could lead to side effects like insomnia, anxiety, and increased heart rate due to the caffeine content. High doses of green tea extract have also been linked to liver injury.

Yes, steeping time significantly affects caffeine levels. A longer steeping time extracts more caffeine, resulting in a more caffeinated brew. To reduce caffeine, steep for a shorter period.

Yes, roasted green teas like Hojicha and teas made from older stems, such as Kukicha, are naturally very low in caffeine. Decaffeinated green tea is also an option for minimal caffeine intake.

Yes. Green tea contains both caffeine and L-theanine, an amino acid that promotes calm and focus. This combination provides a smoother, more sustained energy boost compared to the intense jolt from coffee, helping to prevent jitters and crashes.

Yes, decaffeinated green tea is not entirely caffeine-free. The decaffeination process removes most but not all of the caffeine, typically leaving a minimal amount (less than 12 mg) per serving.