How Much Caffeine Is in Tea Compared to Coffee? | A Clear

You probably already know coffee packs more punch than tea. But the actual numbers might surprise you — especially if you’ve ever wondered whether that afternoon cup of Earl Grey is really giving you a lift or just tasting good. The difference isn’t small, and it isn’t always straightforward.

This article breaks down the caffeine content in tea versus coffee, explains why the numbers vary so much by brewing method, and helps you decide which drink fits your energy needs. Spoiler: your brewing habits matter almost as much as the bean or leaf itself.

Caffeine Content By The Cup

The simplest comparison starts with an eight-ounce serving. According to the Mayo Clinic, brewed coffee averages 80 to 100 mg of caffeine per cup. Black tea sits at roughly 40 to 70 mg, while green tea lands around 30 to 50 mg. That puts coffee at roughly double the caffeine of black tea in most cases.

But not all cups are equal. Instant coffee, for example, averages closer to 60 mg per cup, which overlaps significantly with the upper end of black tea’s range. A strong mug of tea brewed for several minutes can top 70 mg, bumping right up against a weaker drip coffee.

A PubMed study looking at common beverages found the mean caffeine content for brewed coffee is about 85 mg, instant coffee around 60 mg, and bagged tea near 40 mg. That spread makes clear that coffee usually wins the caffeine contest, though the gap narrows depending on what you’re actually drinking.

Why The Numbers Feel Inconsistent

Two cups of “black tea” can have wildly different caffeine levels. The reason comes down to variables most people overlook — water temperature, steeping time, and leaf cut size. A three-minute steep at near-boiling draws far more caffeine than a quick one-minute dip at 170°F.

Many tea drinkers assume green tea is always low in caffeine. Brew it hot enough and long enough, and you can push it toward the lower end of black tea territory. Meanwhile, a light, quick steep of coffee yields less caffeine than a full brew cycle, though few people make coffee that way.

• Steeping time matters most: One study noted that at 75°C (167°F), caffeine levels in tea reached about 10.24 mg per 100 ml after three minutes and didn’t rise much after that. Longer steeps extract more up to a point.
• Water temperature changes everything: Coffee brews at around 195-205°F, while green tea is best at 149-185°F. According to some tea experts, the water temperature and steeping time have a greater impact on tea’s caffeine content than the type of leaf itself.
• Roast and oxidation matter less: Darker coffee roasts don’t necessarily contain more or less caffeine than lighter roasts — the bean variety, grind size, and brew ratio are bigger factors.
• Serving size varies: A standard coffee “cup” is 8 ounces, but many mugs hold 12 to 16 ounces. A 16-ounce mug of coffee easily delivers 160 to 200 mg of caffeine — equivalent to three or four cups of tea.

The takeaway: before comparing caffeine levels, ask how each cup was made. The same tea bag can produce a 30 mg drink or a 70 mg drink depending on the brewing details.

How Tea Leaves Outweigh Coffee Beans

Here’s an interesting twist. Tea leaves, by dry weight, contain more caffeine than coffee beans. Per Healthline’s comparison of caffeine in raw leaves, tea leaves contain about 4% caffeine by weight while coffee beans contain 0.9% to 2.6%. If you chewed raw leaves and beans, the tea leaf would give you more caffeine gram for gram.

So why does brewed coffee end up stronger? The answer comes down to how much leaf or ground is used per cup. A typical cup of coffee uses roughly 10 grams of ground beans. A typical cup of tea uses about 2 to 3 grams of loose leaf or one tea bag. Even though the tea leaf has a higher caffeine percentage, you use far less of it.

The brewing process also makes a difference. Coffee is brewed with water near boiling for several minutes, which extracts more of the available caffeine. Tea, especially green or white varieties, is brewed at lower temperatures and often for shorter periods. The combination of less material and gentler extraction produces the lower caffeine numbers in a finished cup.

Beverage (8 oz)	Typical Caffeine Range	Brewing Temperature
Brewed coffee	80-100 mg	195-205°F
Instant coffee	50-70 mg	Boiling water added
Black tea	40-70 mg	200-212°F
Green tea	30-50 mg	160-185°F
White tea	15-30 mg	160-185°F
Oolong tea	30-50 mg	185-205°F

The range within each beverage type shows why blanket statements about caffeine can be misleading. A short-steeped black tea can fall below a long-steeped green tea, and a strong cup of instant coffee can rival a weak brewed coffee. Individual habits matter.

How To Match Your Drink To Your Caffeine Goal

If you’re trying to manage your caffeine intake, knowing the numbers is only half the battle. The other half is controlling the variables that shift those numbers up or down. Health experts generally consider up to 400 mg of caffeine per day safe for most healthy adults, which translates to roughly four 8-ounce cups of coffee or eight to ten cups of tea.

1. For maximum alertness: Choose brewed coffee. An 8-ounce cup delivers the highest caffeine per volume, with the fastest absorption due to hot extraction.
2. For a moderate lift: Black tea brewed for 3-5 minutes at near-boiling offers 40-70 mg per cup. It provides enough caffeine for focus without the jitteriness some people experience from coffee.
3. For a gentle background buzz: Green tea brewed at 160-175°F for 2-3 minutes typically stays under 40 mg. The lower temperature limits extraction, keeping caffeine levels mild.
4. To minimize caffeine entirely: Herbal teas like peppermint, chamomile, and rooibos contain almost no caffeine. They’re not technically tea (they’re tisanes), but they fill the same role.

Cold brew coffee and cold brew tea follow different rules. Cold brewing extracts caffeine more slowly, so cold brew coffee typically has less caffeine than hot brewed coffee, while cold brew tea can have more than iced tea made by pouring hot tea over ice.

When Coffee And Tea Overlap

The boundaries between coffee and tea caffeine levels aren’t as rigid as most people think. A 1980 study in PubMed found that instant coffee, brewed tea, and a can of cola can all fall within a narrow range of 55 to 65 mg per serving. That means the beverage you choose for a midday pick-me-up could deliver nearly identical caffeine whether it’s coffee, tea, or soda.

Decaffeinated versions shift the picture again. Decaf coffee still contains about 2 to 5 mg per cup, while decaf tea ranges from 1 to 4 mg. Neither is truly caffeine-free, but both are low enough that most health organizations consider them negligible for daily intake limits.

The Mayo Clinic’s caffeine in brewed coffee guide provides the most commonly cited reference ranges, and those ranges overlap with tea at the low end of coffee and the high end of tea. If you order a small coffee at a café, you might get 80 mg. If you brew a strong mug of black tea at home, you could get 70 mg. The difference is real, but not as dramatic as the “coffee has way more caffeine” myth suggests.

Serving Type	Estimated Caffeine
Brewed coffee (8 oz)	80-100 mg
Black tea (8 oz, 3 min steep)	40-70 mg
Instant coffee (8 oz)	50-70 mg
Green tea (8 oz, 2 min steep)	30-50 mg

The Bottom Line

Brewed coffee contains roughly twice the caffeine of black tea per cup, but the gap narrows or widens based on how each drink is prepared. Instant coffee overlaps with strong tea, short-steeped black tea can match green tea, and cold brewing shifts the numbers entirely. For most healthy adults, the choice between tea and coffee comes down to how much caffeine you want and how you prefer to get it.

If you’re adjusting your caffeine intake for health reasons, it’s worth checking the specific brand and brewing method you use — the same tea bag from the same box can give different results depending on your water temperature and steep time.