# How Much Caffeine Is in a Cup of Coffee?

> About 95 mg in an 8 oz cup — but the real range is wide. Milligram figures by serving size, brew method and pot, with the 400 mg guideline.

Topic: Caffeine & Decaf  
Published: 2026-08-30T09:40:00-04:00  
Updated: 2026-08-30T09:40:00-04:00  
Author: Mical Robert, Editor (https://trysix.online/author/mical-robert)  
Canonical: https://trysix.online/how-much-caffeine-in-a-cup-of-coffee

## The short answer

About 95 mg in an 8 oz cup, around 140 mg in a 12 oz mug, and roughly 1,000 mg in a full 12-cup pot. Treat those as midpoints — measured cups of the same drink vary several-fold.

## Key takeaways

- 95 mg per 8 oz is the reference figure. Treat it as the middle of a wide band, not a specification.
- Serving size is the biggest variable most people control. A 16 oz mug is two cups, not one.
- A 12-cup carafe holds about 1,000 mg — the marked 'cups' are 5–6 oz, not mugs.
- The FDA cites 400 mg a day for healthy adults; that figure excludes pregnancy and several conditions.

You will see 95 mg quoted everywhere, usually with no mention that your actual cup could hold half that or double it. If you are keeping an eye on your intake — for sleep, for pregnancy, or because you had a jittery afternoon and want to know why — the spread matters more than the average.

## The headline number, and why it is soft

The commonly quoted figure is 95 mg of caffeine in an 8 oz cup of brewed coffee. It is a reasonable average and it is quoted everywhere, including by the FDA, which puts a typical cup in the 80 to 100 mg range.

What that hides is the spread. A 2003 study in the Journal of Analytical Toxicology measured caffeine in speciality coffees bought commercially and found substantial variation between outlets and between samples of the same drink from the same outlet on different days. A single figure describes the middle of a distribution, not what is in your cup.

> **Why the same drink varies** — Dose, grind, brew time, bean species and how full the cup is poured all move the number, and none of them is standardised in a café. Two 'medium coffees' from the same chain can differ by 50 percent or more.

## By serving size

**Brewed drip coffee at the 95 mg per 8 oz reference rate.**

| Serving | Volume | Caffeine | Note |
| --- | --- | --- | --- |
| Small cup | 6 oz / 180 ml | ~70 mg | The 'cup' on a carafe |
| Standard cup | 8 oz / 240 ml | ~95 mg | The reference figure |
| Mug | 12 oz / 350 ml | ~140 mg | What most people drink |
| Large mug | 16 oz / 475 ml | ~190 mg | Half the daily guideline |
| Travel cup | 20 oz / 590 ml | ~235 mg | One drink |
| 12-cup pot | 60 oz / 1.8 L | ~1,000 mg | Across the whole carafe |

That last row is the one people misjudge. A 12-cup machine's markings use a 5 to 6 oz cup, so a full pot is about 1.8 litres and fills five or six mugs — see [how to use a drip coffee maker](https://trysix.online/how-to-use-a-drip-coffee-maker). Drinking 'half the pot' is roughly 500 mg.

## By brew method

**Figure: Caffeine per standard serving, by preparation**

| Item | Value |
| --- | --- |
| Cold brew, 16 oz (Brewed at a stronger ratio) | 200 mg |
| Drip coffee, 16 oz (The 95 mg baseline, doubled) | 190 mg |
| Double espresso (60 ml) | 126 mg |
| Drip coffee, 8 oz (The reference figure) | 95 mg |
| Instant, 8 oz (Lower than brewed) | 62 mg |
| Single espresso (30 ml) | 63 mg |
| Decaf, 8 oz (Not zero) | 2 mg |

_Typical servings as actually drunk, not per millilitre. Serving size does more work here than extraction efficiency._

**The same drinks, per 100 ml, which reverses much of the ranking.**

| Drink | Per serving | Per 100 ml |
| --- | --- | --- |
| Espresso | 63 mg | ~210 mg |
| Cold brew concentrate | varies | ~150 mg undiluted |
| Drip coffee | 95 mg / 8 oz | ~40 mg |
| Cold brew, ready to drink | 200 mg / 16 oz | ~42 mg |
| Instant | 62 mg / 8 oz | ~26 mg |
| Decaf | 2 mg / 8 oz | ~1 mg |

Espresso leads per millilitre and trails per serving, which is the source of most arguments about it. [Espresso vs coffee](https://trysix.online/espresso-vs-coffee) works the comparison through properly.

## What actually moves the number

1. Serving size. Doubling the cup doubles the caffeine, and no other variable is that clean.
2. Bean species. Robusta carries roughly twice the caffeine of arabica — see [types of coffee beans](https://trysix.online/types-of-coffee-beans).
3. Dose. Brewing at 1:12 rather than 1:16 puts about a third more coffee in the same water.
4. Brew time and grind. Longer contact and finer grind extract more of what is there.
5. Roast level. Real but small — a few percent, and the direction depends on whether you weigh or scoop. [Light vs dark roast](https://trysix.online/light-vs-dark-roast) has the arithmetic.

## Daily limits

The FDA cites 400 mg a day — about four 8 oz cups of brewed coffee — as an amount not generally associated with negative effects for healthy adults. That is a population-level reference, not a personal prescription, and the agency is explicit that people vary in sensitivity and in how quickly they metabolise caffeine.

It does not apply to everyone. Pregnancy guidance is considerably lower, typically around 200 mg. Children and adolescents, people taking medications that interact with caffeine, and anyone with a diagnosed arrhythmia or anxiety disorder are all outside the scope of that figure. Those questions belong with a clinician, not a coffee site.

**Figure: 400 mg in practical terms**

| Item | Value |
| --- | --- |
| 8 oz cups of drip (At 95 mg each) | 4 |
| 12 oz mugs (At ~140 mg each) | 3 |
| 16 oz cold brews (At ~200 mg each) | 2 |
| Double espressos (At 126 mg each) | 3 |

_The FDA's reference figure for healthy adults, expressed as drinks. Not a target._

> **Where these numbers are least reliable** — Café drinks. A shop's dose, grind and shot count are not published and vary by branch and by barista. If you need to control intake precisely, brewing at home with a known dose is the only way to know what you are actually drinking.

## Decaf is not zero

An 8 oz cup of decaf holds roughly 2 mg of caffeine, and a decaf espresso shot 3 to 15 mg. US regulations require at least 97 percent of the caffeine to be removed, which leaves a small residue by design. For most people that is negligible; for someone extremely sensitive drinking several cups, it is not nothing. [Does decaf coffee have caffeine](https://trysix.online/does-decaf-coffee-have-caffeine) has the detail.

## Frequently asked questions

### How much caffeine is in a cup of coffee?

About 95 mg in an 8 oz cup of brewed coffee, with the FDA citing a typical range of 80 to 100 mg. Real measurements vary considerably, because dose, grind, brew time and bean species are not standardised — especially in cafés.

### How much caffeine is in a full pot of coffee?

A 12-cup carafe holds roughly 1,000 mg. The 'cups' marked on a machine are 5 to 6 oz rather than mugs, so a full pot is about 1.8 litres and fills five or six mugs — around 190 mg per mug.

### Is 400 mg of caffeine a day safe?

The FDA cites 400 mg as not generally associated with negative effects for healthy adults — about four 8 oz cups. It is a population reference, not personal advice, and it does not apply during pregnancy, to children, or to people with certain heart or anxiety conditions.

### Which coffee has the most caffeine per serving?

Usually the largest one. A 16 oz cold brew or drip coffee beats a double espresso, because serving size dominates. Per millilitre espresso wins easily, but almost nobody drinks a litre of it.

## Sources

- [Spilling the Beans: How Much Caffeine is Too Much?](https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much) — U.S. Food and Drug Administration. Supports the 80–100 mg per cup range and the 400 mg per day reference figure for healthy adults.
- [Caffeine Content of Specialty Coffees](https://doi.org/10.1093/jat/27.7.520) — Journal of Analytical Toxicology (2003) (DOI 10.1093/jat/27.7.520). Supports the finding that commercially served coffee varies substantially in measured caffeine content.
- [FoodData Central](https://fdc.nal.usda.gov/) — USDA Agricultural Research Service. Supports the reference composition data used for the per-serving and per-100 ml figures.

## Related articles

- https://trysix.online/what-coffee-has-the-most-caffeine
- https://trysix.online/does-decaf-coffee-have-caffeine
- https://trysix.online/espresso-vs-coffee
- https://trysix.online/light-vs-dark-roast

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