How Much Caffeine Is In a Cup of Coffee?
How Much Caffeine Is In a Cup of Coffee?
A standard 8-ounce cup of coffee contains between 80 and 100 milligrams of caffeine on average. But if you've ever wondered why some cups hit harder than others, you're asking the right question, because the real answer is: it depends.
A standard 8-ounce cup of coffee contains between 80 and 100 milligrams of caffeine on average. But if you've ever wondered why some cups hit harder than others, you're asking the right question, because the real answer is: it depends.
The caffeine content in your morning brew varies based on the type of coffee bean, how it's roasted, how you brew it, and even how much coffee you use. If you've been operating on guesswork about your caffeine intake, this guide will give you the clarity you need.

Caffeine Content by Brewing Method
How you brew your coffee has a massive impact on caffeine levels. Here's what you're actually getting per 8-ounce serving:
- Drip coffee: 80-100 mg (the standard)
- French press: 80-120 mg (longer steep time extracts more caffeine)
- Pour over: 80-100 mg (similar to drip)
- Cold brew: 150-200 mg (steeps for 12-24 hours, significantly higher)
- Espresso: 60-80 mg per 1-ounce shot (but who stops at one ounce?)
- Instant coffee: 30-90 mg (varies wildly by brand)
Notice that espresso actually has less caffeine per ounce than drip coffee. The confusion comes from serving size, a typical latte has 1-2 shots of espresso (60-160 mg), while a standard coffee cup is 8-12 ounces (80-150 mg).
Why Cold Brew Packs More Punch
Cold brew uses a higher coffee-to-water ratio and steeps for significantly longer than hot brewing methods. This extended contact time pulls more caffeine from the beans. If you're sensitive to caffeine and drinking cold brew like it's regular iced coffee, that might explain the jitters.
Does Roast Level Affect Caffeine?
Here's where coffee mythology meets reality. Many people believe dark roasts have more caffeine because they taste stronger and more intense. The truth? Light roasts actually have slightly more caffeine, but the difference is negligible.
When coffee beans are roasted longer, they lose some mass (water content and other compounds burn off). By weight, a light roast bean has marginally more caffeine than a dark roast bean. But by volume, they're nearly identical because dark roasted beans are larger and less dense.
In practical terms: if you scoop your coffee by volume (like most people do), roast level makes almost no difference to your caffeine intake. If you weigh your coffee with a scale, light roasts will give you slightly more caffeine per gram.
What About Air-Roasted Coffee?
At Ember, we air-roast our beans instead of using traditional drum roasting. The caffeine content stays the same, air roasting doesn't affect caffeine levels. What it does affect is acidity and flavor clarity. The beans never touch a scorching metal drum, which means you get cleaner flavor without the burnt notes that can come from drum roasting.
Arabica vs Robusta: The Bean Makes a Difference
The species of coffee bean matters more than roast level when it comes to caffeine:
- Arabica beans: 1.2-1.5% caffeine by weight (smoother, more complex flavor)
- Robusta beans: 2.2-2.7% caffeine by weight (harsher taste, more bitter)
Most specialty coffee, including everything we roast at Ember, is 100% Arabica. Robusta is typically used in instant coffee, cheaper blends, and traditional Italian espresso to add crema and caffeine kick.
If you've had a cup of coffee that tasted particularly harsh but kept you wired all day, it probably contained Robusta beans.

How Coffee-to-Water Ratio Changes Caffeine
This is the variable you actually control every time you brew. Use more coffee grounds? You get more caffeine. It's that simple.
The standard ratio is 1:16 (1 gram of coffee to 16 grams of water), which produces that 80-100 mg caffeine range in an 8-ounce cup. But if you like your coffee stronger and use a 1:14 ratio, you're increasing your caffeine intake proportionally.
This is why asking "how much caffeine is in coffee?" without specifying how you brew it is like asking "how fast does a car go?", technically answerable, but missing crucial details.
What This Means for Your Daily Caffeine Intake
The FDA considers 400 mg of caffeine per day safe for most healthy adults. That's roughly four 8-ounce cups of drip coffee, or two large cold brews.
But everyone metabolizes caffeine differently. Some people have a genetic variation that makes them slow caffeine metabolizers, they feel effects longer and more intensely. If you're one of those people, even 200 mg might feel like too much.
Signs You Might Be Getting Too Much Caffeine
- Jitters or anxiety after your normal amount
- Trouble falling asleep even when you stop drinking coffee by noon
- Rapid heartbeat or palpitations
- Digestive discomfort or acid reflux
- Headaches when you skip your usual coffee
If you're experiencing these symptoms, it might not be the caffeine alone. Coffee acidity can cause similar issues. That's one reason we focus on air-roasting, it produces a naturally less acidic cup that's easier on your system.
Does Decaf Really Have Zero Caffeine?
Not quite. Decaf coffee still contains about 2-5 mg of caffeine per 8-ounce cup. The decaffeination process removes approximately 97% of the caffeine, but not all of it.
For most people, 2-5 mg is negligible. But if you're extremely sensitive to caffeine or avoiding it entirely for medical reasons, be aware that "decaf" isn't the same as "caffeine-free."
Frequently Asked Questions
Does stronger tasting coffee have more caffeine?
Not necessarily. Strength refers to flavor intensity, which comes from the coffee-to-water ratio and roast level. A dark roast might taste "stronger" but have the same caffeine as a light roast. Cold brew tastes smooth but has significantly more caffeine than hot coffee.
How much caffeine is in a Starbucks coffee?
A Starbucks Grande (16 oz) Pike Place Roast contains approximately 310 mg of caffeine, nearly four times the amount in a standard 8-ounce cup. Their serving sizes are much larger than the traditional "cup of coffee" measurements.
Can I reduce caffeine by brewing coffee for less time?
Yes, but you'll also get weaker coffee. Caffeine extracts relatively quickly, most of it comes out in the first few minutes of brewing. If you want less caffeine without sacrificing flavor, try using fewer coffee grounds or mixing regular with decaf.
Does adding milk or cream reduce caffeine?
No, it dilutes the flavor but doesn't remove or neutralize caffeine. A latte has the same caffeine as the espresso shots it contains, the milk just adds volume.
Why do I feel more jittery from some coffees than others?
It could be caffeine content, but it's often acidity. High-acid coffees can cause physical discomfort that feels similar to too much caffeine. How the beans are processed, roasted, and brewed all affect acidity levels.

The Bottom Line on Coffee and Caffeine
An 8-ounce cup of coffee typically contains 80-100 mg of caffeine, but your actual intake depends on brew method, bean type, and how much coffee you use. Cold brew and espresso drinks can contain significantly more, while factors like roast level make surprisingly little difference.
If you're trying to manage your caffeine intake, pay attention to serving size and brewing method first. And if you find yourself dealing with jitters or acid reflux, it might not be the caffeine at all, it could be how your coffee is roasted.
Want coffee that's easier on your system without sacrificing flavor?