Does tea have as much caffeine as coffee?

Caffeine is a stimulant that is found in coffee, tea and chocolate. It is what gives you that alert feeling after having your first cup of brew in the morning. The amount of caffeine in different foods and drinks varies significantly. So does coffee or tea have more caffeine?

Tea vs coffee caffeine content

Before being brewed, tea leaves contain more caffeine than coffee beans do. However after brewing, coffee generally tends to contain more caffeine than tea does. A cup of coffee contains around 95 mg of caffeine, whereas a cup of tea contains around 40 mg.

It is important to note that these numbers are average estimates. The actual amount of caffeine in a given cup of tea or coffee is determined by many factors.

Tea caffeine content

Before learning more about it, I thought there were only two kinds of tea, “normal tea” and “green tea”, both of which were obtained from different plants. I was surprised to learn that there are actually 5 main categories of tea, namely black, oolong, green, white and pu-erh and they are all made from the leaves of the Camellia sinensis plant. Two major varieties of this plant are grown, Sinensis and Assamica, with the latter having more caffeine.

Each of these 5 categories has hundreds of different varieties. For example, Matcha, Sencha, Hojicha and Bancha are all varieties of green tea. Darjeeling, Keemun and Ceylon are varieties of black tea.

Tea leaves are plucked and then allowed to oxidize. The degree of oxidation determines the type of tea that you get. White tea is the least oxidized whereas black tea is the most oxidized. Black tea also tends to contain the most amount of caffeine, at 40 – 60 mg per cup, whereas white tea tends to contain the least, at 10 -15 mg per cup. Oolong & green tea have fairly similar amounts of caffeine and lie in between black and white tea.

The way in which the tea is brewed also determines caffeine content.

  • Brew length – the longer you seep the tea leaves in water for, the more caffeine it will have. This is due to the simple reason that longer exposure equates to more absorption.
  • Temperature of water – the temperature of the water determines how much caffeine is absorbed. Boiling hot water will result in more caffeine being absorbed than luke warm water.
  • Grade of the tea leaves – lower grade tea leaves are more broken up than higher grade. This means they have more surface area and so result in more caffeine being absorbed.

Caffeine in coffee

As mentioned above, brewed coffee tends to have more coffee than brewed tea. However the actual amount of caffeine in a cup of coffee can also vary greatly, depending on a number of factors:

  • The type of bean – different beans have different amounts of caffeine. There are two main varieties, Arabica and Robusta, with the latter containing more caffeine. In general, the lighter the bean, the more caffeine it tends to contain.
  • Fineness of beans – similar to the grade of tea leaves, coffee beans that are ground more finely will have a larger surface area, leading to more caffeine being absorbed.
  • Duration of brew – the longer you brew the beans, the more caffeine you get

Is caffeine healthy?

Caffeine has both its pros & cons, and people tolerate it differently. There have been a number of studies that have investigated how caffeine affects the body. As with many studies in health and nutrition, some study results contradict others and so further research is required. Here are a few of the benefits.

  • The first and most obvious benefit is that caffeine improves energy levels and alertness. This is one of the reasons why so many people have a hot cup of tea or coffee first thing in the morning. Studies have shown that caffeine improves general cognitive function.
  • Caffeine can improve physical performance by increasing Adrenaline levels in the blood and making body fat available as a source of fuel. It can improve physical performance by up to 12%.
  • Studies seem to suggest that caffeine can help lower the risk of developing Parkinson’s disease.
  • Caffeine consumption could help with weight management, as explained in this study.
  • This study found that even small amounts of caffeine can improve lung function and could help people suffering from asthma, however more research does need to be carried out.

Caffeine also has its negative sides:

  • Caffeine consumption can lead to insomnia and sleeping problems. This is why it is not recommended to have coffee at least 4 – 6 hours before bedtime.
  • It can cause indigestion, especially if consumed on an empty stomach.
  • Over consumption can cause headaches.

It is recommended that you consume no more than 400 mg of caffeine per day, which is the amount found in roughly 4 cups of brewed coffee. Always speak to a qualified medical professional before increasing caffeine intake, especially if you are on medication.


Brewed coffee tends to contain significantly more caffeine than brewed tea. The amount of caffeine per cup varies and is dependent on a number of different factors.

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