How Much Caffeine is in Coffee?
Caffeine content in coffee varies widely depending on the type of coffee bean, brewing method, and serving size. On average, a 240ml (8oz) cup of brewed coffee contains around 95mg of caffeine, but this can range from as low as 30mg to over 200mg. Espresso shots, instant coffee, and decaf all have different caffeine levels.
Understanding these variations is essential for managing caffeine intake, whether you're looking for a morning boost or trying to cut back. Below, we break down the caffeine content in different coffee types and factors that influence its levels.
Caffeine Content by Coffee Type
1. Brewed Coffee (Drip or Filter)
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Average caffeine content: 70–140mg per 240ml (8oz)
- Factors affecting caffeine levels: Brewing time, grind size, and coffee-to-water ratio
- Source: Healthline - Caffeine in Coffee
2. Espresso
- Average caffeine content: 63mg per single shot, 126mg for a double shot
- Stronger concentration: Espresso has more caffeine per ounce but is consumed in smaller quantities
- Source: Mayo Clinic - Caffeine Content
3. Instant Coffee
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Average caffeine content: 30–90mg per 240ml (8oz)
- Why lower? Instant coffee is made from dried brewed coffee, often with a lower caffeine concentration
- Source: National Library of Medicine - Caffeine in Beverages
4. Decaffeinated Coffee
- Average caffeine content: 2–5mg per 240ml (8oz) cup
- Not entirely caffeine-free: Decaf still contains small traces of caffeine
- Source: FDA - Decaf Coffee Regulation
Factors That Affect Caffeine Content
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Type of Coffee Bean
- Robusta beans contain about twice the caffeine of Arabica beans.
- Source: Journal of Agricultural and Food Chemistry
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Brewing Method
- Longer brewing times extract more caffeine.
- French press and cold brew have higher caffeine due to extended steeping.
- Source: Scientific Reports - Caffeine Extraction
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Serving Size
- Larger cups mean more caffeine—some commercial coffee chains serve cups with over 300mg per serving.
- Source: Starbucks Caffeine Guide
How Much Caffeine Is Safe?
The FDA recommends a maximum daily intake of 400mg of caffeine for most adults—roughly four 240ml (8oz) cups of coffee. Exceeding this may cause restlessness, anxiety, and sleep disturbances.
- Source: FDA - Caffeine Safety
Final Thoughts
Caffeine levels in coffee can vary significantly based on type, preparation, and serving size. Whether you prefer a strong espresso shot or a mild decaf, understanding the caffeine content can help you make informed choices. If you're sensitive to caffeine, consider lower-caffeine options or decaf. Robusta-based or cold brew options may be best for those needing an extra kick.