What Has More Caffeine, Coke or Tea? A Nutritional Showdown

October 19, 2025 •

3 min read

While a standard 12-ounce can of Coca-Cola contains a fixed 32–34mg of caffeine, the amount in a cup of tea is highly variable and can range dramatically based on the type and brewing method. This means that sometimes tea has more caffeine, and sometimes Coke does, making the comparison more complex than it first appears.

Quick Summary

This article compares the caffeine levels in Coke and tea by examining Coke's consistent dose versus tea's wide variability, which depends on factors like processing and brewing. It also covers the significant nutritional differences and potential health impacts of each beverage.

Key Points

Tea's variability: Caffeine in tea fluctuates widely based on brewing and type, unlike Coke's fixed amount.
Black tea's potency: A typical cup of black tea (40–70 mg) often contains more caffeine than a standard can of Coke (32–34 mg).
Healthier profile: Unsweetened tea provides antioxidants and other benefits like L-theanine, while Coke offers little nutritional value and high sugar content.
Calm focus: The L-theanine in tea promotes a relaxed, sustained energy boost, helping to prevent the jitters associated with other caffeinated drinks.
Brewing control: You can influence the caffeine in your tea by adjusting the steeping time, water temperature, and amount of tea leaves.
Diet Coke's caffeine: Surprisingly, Diet Coke (around 42 mg) contains more caffeine than regular Coca-Cola.

The Consistent Dose of Coke vs. The Variable World of Tea

Comparing the caffeine in Coke and tea highlights a key difference: consistency. Coca-Cola has a precise, regulated caffeine amount, while tea's caffeine level varies widely due to factors like type and preparation. This variability is why the question of which has more caffeine is complex, and why an average cup of black tea can contain more caffeine than a can of Coke.

The Fixed Caffeine in Coca-Cola

Coca-Cola offers reliable nutritional information. A 12-ounce (355 ml) can of classic Coke contains a consistent 32 to 34 milligrams (mg) of caffeine. Diet Coke has slightly more, with around 42 mg in the same serving size. The company maintains this uniformity, so the caffeine dose is predictable.

The Highly Variable Caffeine in Tea

Tea, from the Camellia sinensis plant, is different. Its caffeine content depends on the tea type, processing, and brewing method. While black tea may have more caffeine than Coke, white tea can have significantly less. Average caffeine content per 8-ounce (237 ml) serving for various teas includes:

Black Tea: 40–70 mg
Oolong Tea: 30–60 mg
Green Tea: 20–45 mg
Matcha (Green): 35–88+ mg (consuming the whole leaf leads to higher levels)
White Tea: 15–30 mg
Herbal Tea: 0 mg (naturally caffeine-free)

Factors Influencing Tea's Caffeine Level

Several factors can alter the caffeine in your tea:

Brewing Temperature: Hotter water extracts more caffeine. Black tea, brewed with hotter water, often has higher caffeine than green tea, which uses cooler water.
Steeping Time: Longer steeping releases more caffeine.
Leaf Size: Smaller leaf particles in tea bags release caffeine faster than whole leaves.
Harvest Time and Processing: Younger leaves and buds or teas from warmer climates often have more caffeine. Oxidation also contributes, with black tea being more oxidized than green tea.

Comparative Look at Caffeine Content

Below is a comparison of average caffeine levels in standard servings of Coke and various teas.


Beverage	Serving Size	Average Caffeine (mg)	Notes
Coca-Cola Classic	12 oz (355 ml)	32–34 mg	Consistent and regulated dose
Diet Coke	12 oz (355 ml)	42 mg	Higher than regular Coke
Black Tea	8 oz (237 ml)	40–70 mg	Dependent on brew time and temperature
Green Tea	8 oz (237 ml)	20–45 mg	Milder caffeine content, less extraction
Oolong Tea	8 oz (237 ml)	30–60 mg	Falls between black and green tea
White Tea	8 oz (237 ml)	15–30 mg	Lowest caffeine of traditional teas

Beyond Caffeine: Nutritional Differences and Health Impacts

The choice between Coke and tea involves significant nutritional and health considerations beyond just caffeine.

The Health Profile of Tea

Tea is known for its health benefits, largely from antioxidants and other compounds.

Antioxidants: Teas, especially green and black, contain antioxidants that reduce inflammation and may lower the risk of chronic diseases like heart disease, diabetes, and certain cancers.
L-Theanine: This amino acid in tea works with caffeine to promote calm alertness, providing a smoother energy boost without jitters.
Hydration: Unsweetened tea contributes to fluid intake.

The Drawbacks of Coca-Cola

Soft drinks like Coke are generally considered unhealthy due to high sugar and acidity, with minimal nutritional value.

High Sugar Content: A 12-ounce can of Coke has about 39 grams of sugar, adding calories without nutrients. Frequent consumption is linked to obesity, type 2 diabetes, and heart disease.
Dental Erosion: The acidity and sugar in soda can cause tooth decay and enamel erosion.
Synthetic Ingredients: Sodas contain synthetic caffeine, artificial flavors, and other additives, unlike tea's natural compounds.

How to Make the Healthier Choice for You

While the caffeine content can vary, unsweetened tea is generally the healthier choice compared to Coke. Tea's variability allows for caffeine control, and its antioxidants and L-theanine provide health benefits and a calm energy boost, unlike Coke's empty calories and health risks. For more detailed information, resources like the Harvard T.H. Chan School of Public Health are helpful.

Frequently Asked Questions

Yes, a 12-ounce can of Diet Coke contains about 42 mg of caffeine, which is slightly more than the 32–34 mg found in a 12-ounce can of regular Coca-Cola.

Yes, you can control the caffeine level by adjusting the brewing time, water temperature, and using less tea. Steeping for a shorter duration or with cooler water will extract less caffeine.

The caffeine effect differs due to tea's L-theanine content, which promotes a more relaxed, sustained energy boost. Soda, with its synthetic caffeine and sugar, often leads to a quicker, more intense spike followed by a crash.

Matcha, which is powdered green tea where you consume the entire leaf, generally has the highest caffeine content among teas, followed by black tea.

Unsweetened iced tea is generally much healthier than Coke. However, many commercially available iced teas are high in sugar, which can negate some of the health benefits.

Excessive consumption of soda is linked to health problems such as obesity, type 2 diabetes, heart disease, and dental erosion due to its high sugar and acidic content.

Yes, tea grade affects caffeine. Broken tea leaves or 'fannings' often found in tea bags have a larger surface area and release caffeine more quickly than whole leaf teas.