How Much Caffeine Is Actually in Tea? A Real Comparison by Type

"Green tea has less caffeine than black tea" is the version everyone's heard, and it's not quite wrong — but it's a much bigger oversimplification than most people realize, and it skips the variable that actually matters most: how you brew it.

What the actual numbers look like

Comparisons across tea types generally land somewhere in these ranges per 8 oz (about 240 ml) cup: white tea around 15–35 mg, green tea around 20–40 mg, oolong around 30–50 mg, black tea around 40–70 mg, and pu-erh in a comparable range to black tea, often cited around 60–70 mg for shu (ripe) pu-erh. Those ranges overlap a lot — the top of green tea's range beats the bottom of black tea's, which is the first sign that "type" alone doesn't fully predict caffeine content.

A peer-reviewed comparison of brewed infusions found caffeine levels highest in black and yellow tea (roughly 14 mg and 13.8 mg per 200 ml), notably higher than green, white, and oolong (roughly 11 mg, 5.8 mg, and 4 mg per 200 ml in that study), while pu-erh came in comparable to black tea at around 13 mg per 200 ml. The same research found something arguably more useful than the type comparison itself: longer brewing time significantly raised caffeine content, regardless of tea type.

Why brewing time matters more than the label

This is the part most caffeine-comparison charts leave out entirely. Caffeine extracts into water steadily throughout a steep — a short, hot gongfu-style infusion pulls out less than a long Western-style steep of the same leaf, even though it's the same tea. This is also why the same leaf tastes progressively less caffeinated across multiple gongfu infusions: oolong specifically has been measured dropping from roughly 30–50 mg in the first cup to 15–25 mg in the second and just 5–10 mg by the third, using the same leaves each time. If you're re-steeping gongfu-style — see our brew calculator for timing by tea type — your third or fourth cup of the day is carrying a fraction of the caffeine your first one did, even from the exact same leaf.

The practical version

If you're trying to manage caffeine intake, tea type is a reasonable starting filter but not a reliable ceiling: white tea and lighter green tea sit lowest on average, oolong in the middle, and red/black tea and shu pu-erh highest — but a long-steeped green tea can out-caffeinate a quick-steeped black tea. The two levers that actually matter within any single tea are steep time and how many infusions deep you are. If you want caffeine specifically for a real lift, brew hotter and longer and drink the first infusion; if you want the ritual and flavor with less caffeine, gongfu-brew the same leaf and lean on the later steeps.