How much caffeine is in real tea?

December 2, 2025 •

4 min read

While tea is the second most consumed beverage globally after water, the amount of caffeine in real tea can vary widely, with an average 8-ounce cup of black tea containing 40–70 mg. The exact quantity depends on numerous factors, from the specific tea varietal to how it is prepared, making a precise figure difficult to pinpoint without laboratory testing.

Quick Summary

An overview of caffeine levels in different types of real tea, exploring the various factors that influence the final concentration in a brewed cup. Includes a comparison of black, green, white, and oolong teas, alongside important brewing considerations.

Key Points

Caffeine Varies Widely: The amount of caffeine in real tea depends on many factors, with black tea generally having more and white tea less, but with a large overlap in ranges depending on preparation.
Processing and Origin: The level of leaf oxidation (from minimal for white tea to full for black tea) and the specific varietal of the Camellia sinensis plant are major determinants of caffeine content.
Brewing is Key: You can manage your caffeine intake by adjusting brewing variables. Hotter water and longer steeping times extract more caffeine from the leaves.
Matcha is an Exception: As a powdered, shade-grown green tea where the entire leaf is consumed, matcha delivers a higher and more concentrated dose of caffeine than a standard steeped tea.
Harvest Impacts Content: Younger tea leaves and buds, often used for higher-grade teas, contain more caffeine than older, more mature leaves.
Herbal Teas are Different: Herbal infusions, or tisanes, are not from the Camellia sinensis plant and are naturally caffeine-free, offering a reliable zero-caffeine option.

The Basics: What is Real Tea?

Real tea refers to beverages made from the leaves of the Camellia sinensis plant. The four primary types are black, green, white, and oolong. Herbal teas, or tisanes, are not from the Camellia sinensis plant and are naturally caffeine-free. The processing of the leaves largely determines the tea's category, which in turn influences its caffeine content.

How Much Caffeine Is In Different Types of Tea?

The caffeine content in a typical 8-ounce cup varies significantly by tea type, as outlined below:

Black Tea: Generally contains the highest levels of caffeine, ranging from 40 to 70 mg per cup. This is due to the full oxidation process the leaves undergo, and varieties like Assamica often have higher natural levels.
Oolong Tea: Falling between black and green tea, oolong typically contains 30 to 50 mg of caffeine per cup. As a partially oxidized tea, its caffeine level is affected by its specific processing.
Green Tea: Contains less caffeine than black tea, with concentrations usually between 20 and 45 mg per cup. Green tea leaves are unoxidized, a process that helps keep caffeine levels lower.
White Tea: Often has the lowest caffeine content, with levels typically between 15 and 30 mg per cup. This is primarily because white tea is minimally processed and uses the youngest buds and leaves. However, some white teas made with tips harvested in the spring can be higher in caffeine.
Matcha: A notable exception, matcha green tea is consumed as a powder, meaning you ingest the entire leaf rather than just an infusion. Because of this and its shade-grown origins, a single serving of matcha can contain 30–70 mg of caffeine, making it more potent than a standard cup of brewed tea.

Factors That Influence a Tea’s Caffeine Content

Several variables can alter the final caffeine concentration in your cup. Understanding these can help you control your intake.

Varietal of the Tea Plant: The Camellia sinensis plant has two major varieties: sinensis and assamica. The assamica varietal, native to India and used for many black teas, naturally has higher caffeine levels. The sinensis varietal, native to China, generally has lower levels.
Harvest Time: Young tea shoots and buds, typically harvested in the spring, tend to have a higher concentration of caffeine than older, more mature leaves. This is why some high-end white teas, like Silver Needle, can have more caffeine than expected.
Processing Method: How the leaves are handled—from oxidation for black tea to minimal processing for white tea—plays a large role in the final caffeine level. For example, teas that use whole, unfractured leaves release caffeine more slowly than those using broken leaf pieces.
Brewing Temperature: Higher water temperatures extract more caffeine from the leaves. Brewing black tea with boiling water will release more caffeine than brewing green tea with cooler water.
Steeping Time: The longer the tea steeps, the more caffeine is infused into the water. A short, 1-minute steep will yield a significantly lower caffeine dose than a 5-minute steep with the same leaves.
Leaf Quantity: Using more tea leaves for the same amount of water will increase the caffeine concentration. Many people inadvertently increase their caffeine intake by using more tea for a stronger flavor.

A Comparison of Tea Caffeine Levels


Tea Type	Typical Caffeine Range (8 oz cup)	Key Factors	Note
Black	40–70 mg	Full oxidation, often from assamica plant	Higher heat and longer steep times increase extraction.
Oolong	30–50 mg	Partial oxidation process	Can vary widely based on oxidation level and brewing.
Green	20–45 mg	Unoxidized leaves, often from sinensis plant	Cooler water and shorter steep times are recommended.
White	15–30 mg	Minimal processing, young buds	Can vary if made from tips vs. older leaves.
Matcha	30–70 mg (per serving)	Ingesting the entire powdered leaf	Often higher due to shade-growing and full consumption.

What This Means for Tea Drinkers

Because of all these variables, relying solely on the tea type to manage your caffeine intake can be misleading. A long-steeped green tea can potentially contain more caffeine than a quick, light infusion of black tea. It is most effective to control the final caffeine level in your cup by adjusting your brewing process. For those looking for a lower caffeine beverage, opting for decaffeinated versions or naturally caffeine-free herbal teas is the most reliable method.

Conclusion

While black tea is often cited as having the most caffeine and white tea the least among true teas, this is only a general guideline. The actual amount of caffeine in real tea is a complex interplay of the specific tea varietal, its processing, and your brewing choices. By understanding these factors, you can brew your tea to your personal preference for both flavor and caffeine level. For reliable, low-caffeine options, adjusting your steeping time or choosing herbal infusions are the best strategies. For further reading on the chemical composition of tea and its effects, you can refer to authoritative sources like articles from the National Institutes of Health.

Key takeaways

Varies by Type: On average, black tea has the highest caffeine (40-70 mg), followed by oolong (30-50 mg), green (20-45 mg), and white (15-30 mg) tea per 8-ounce cup.
Processing Matters: The level of oxidation and processing, which define the tea type, significantly impact the caffeine content.
Brewing Controls Intake: The amount of caffeine extracted depends heavily on water temperature, steeping time, and the quantity of leaves used.
Matcha Is Different: Due to consuming the entire powdered leaf, a serving of matcha typically contains a higher caffeine concentration than most other brewed teas.
Consider Other Factors: The specific plant varietal, harvest season, and even growing conditions (like shade-grown vs. sun-grown) also affect the final caffeine level.

Frequently Asked Questions

Yes, on average, black tea contains more caffeine than green tea due to the oxidation process it undergoes. However, the actual caffeine level can overlap depending on brewing methods, leaf quality, and steeping time.

Yes, you can reduce the caffeine by using cooler water and steeping the tea for a shorter amount of time. A common method is a quick 30-second initial rinse and discard, which removes some surface caffeine, but this will also affect the flavor.

No, white tea contains caffeine, though it typically has the lowest amount among true teas, ranging from 15 to 30 mg per cup. Only herbal teas are naturally caffeine-free.

Matcha is made from powdered green tea leaves, so when you drink it, you are consuming the entire leaf, not just the brewed infusion. This, combined with its shade-growing process, results in a more concentrated caffeine intake.

Hotter water more efficiently extracts caffeine from the tea leaves. Using boiling water will release more caffeine than brewing with cooler water, as is common for green and white teas.

Decaffeinated teas are real teas from the Camellia sinensis plant that have undergone a process to remove most of the caffeine, though trace amounts may remain. Naturally caffeine-free teas, or herbal tisanes, are made from non-Camellia sinensis plants like chamomile or peppermint and contain no caffeine naturally.

Yes, steeping time is one of the most important factors. The longer you steep your tea, the more caffeine is released into the water, resulting in a more caffeinated brew.