Thai tea contains a moderate amount of caffeine, roughly comparable to a standard cup of black tea. A typical serving delivers around 50 to 90 milligrams of caffeine depending on the base tea used, how long it’s brewed, and how much ice dilutes the final drink. That puts it well below coffee but on par with or slightly above most other tea-based beverages.
How Much Caffeine Is in Thai Tea
Thai tea is built on a base of strong black tea, usually a Ceylon or Assam variety. Ceylon tea contains roughly 50 to 70 milligrams of caffeine per cup when brewed from loose leaves, and 55 to 80 milligrams from tea bags. Assam tea runs higher, averaging 50 to 90 milligrams per cup from loose leaf and 60 to 100 milligrams from bags. Assam is naturally one of the most caffeinated black teas, which is one reason Thai tea can pack a noticeable kick.
The way Thai tea is prepared matters quite a bit. Traditional recipes call for brewing the tea concentrate strong, then pouring about three-quarters of a cup of that base over a full pint glass of ice. The ice dilutes the concentrate significantly, which pulls the caffeine content of your actual drink lower than what you’d get from sipping a straight cup of hot black tea. Still, if a shop brews extra-strong concentrate or uses less ice, you could end up closer to the upper range.
Commercial Thai tea mixes add another variable. Some popular mixes, like Pantai brand, list green tea (Camellia sinensis) rather than black tea as the base ingredient, alongside food coloring for that signature orange hue. Green tea typically contains less caffeine than black tea, so a mix like this would land on the lower end of the spectrum. There’s no standardized caffeine amount across brands, and most commercial mixes don’t print caffeine on the label, so the exact number varies.
Thai Tea vs. Coffee and Other Drinks
An 8-ounce cup of brewed coffee contains roughly 80 to 100 milligrams of caffeine, and a 16-ounce coffeehouse serving can hit 200 milligrams or more. A glass of Thai iced tea falls comfortably below that. If you’re switching from coffee to Thai tea, you’ll likely get about half the caffeine per serving, sometimes less.
Compared to other teas, Thai tea sits in a similar range as English breakfast tea or chai, both of which use strong black tea bases. It generally contains more caffeine than green tea (around 25 to 50 milligrams per cup) and significantly more than herbal teas, which are naturally caffeine-free. If you’re sensitive to caffeine, Thai tea will absolutely affect you, but it’s not unusually high among tea-based drinks.
Why Thai Tea Can Feel More Energizing
Many people report that Thai tea gives them a noticeable energy boost that feels bigger than its caffeine content alone would suggest. The likely explanation is sugar. Traditional Thai iced tea is made with sweetened condensed milk and often additional sugar, which can deliver a rapid blood sugar spike alongside the caffeine. That combination of moderate caffeine plus a sugar rush creates a more pronounced “buzz” than plain brewed tea.
Black tea also contains an amino acid that promotes calm alertness, which is why tea drinkers often describe the caffeine effect as smoother and less jittery than coffee. With Thai tea, though, the heavy sugar load can override that smoothness, making the energy feel more like a spike and crash.
Lowering the Caffeine in Thai Tea
If you enjoy Thai tea’s creamy, spiced flavor but want less caffeine, you have a few practical options. Brewing the tea base for a shorter time reduces caffeine extraction. Using more ice or a larger glass dilutes the concentrate further. Asking for half-strength concentrate at a restaurant works too, though not every shop will accommodate that.
For a fully caffeine-free version, rooibos tea makes a solid substitute. Rooibos is naturally caffeine-free, has a warm, slightly sweet flavor, and takes on the creamy richness of condensed or evaporated milk surprisingly well. It won’t taste identical to traditional Thai tea, but it captures the same general profile. Some home recipes use rooibos as a direct swap for the black tea base, keeping everything else the same.
Decaf black tea is another option, though it still contains trace amounts of caffeine (typically 2 to 5 milligrams per cup). Combined with the strong brewing method used for Thai tea, decaf versions will have slightly more residual caffeine than a standard decaf cup, but still far less than the regular version.