How much caffeine is in decaf coffee?

An 8 fl oz cup of decaf coffee has 2 to 15 mg of caffeine.

That's a small fraction of a cup of brewed coffee, and 2% of the 400 mg a day the FDA cites for most healthy adults.

Source: USDA FoodData Central · checked 10 Nov 2026

When did you have it?

Had at 3 pm, about 2.8 mg is still in you at an 11 pm bedtime. That should not affect most people’s sleep.

Ranges: the chart uses the middle of the published range (8 mg for this size).

Bedtime

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Latest time to drink it

For an 11 pm bedtime, an 8 fl oz cup of decaf coffee stays under the 50 mg most people sleep fine with, even late in the evening. The table works it out for other bedtimes and for how sensitive you are: it is the latest time to start one so that the caffeine left stays under the line all night.

Bedtime	Very sensitive under 25 mg	Average under 50 mg	Not very sensitive under 100 mg
9 pm	Any time	Any time	Any time
10 pm	Any time	Any time	Any time
11 pm	Any time	Any time	Any time
Midnight	Any time	Any time	Any time
1 am	Any time	Any time	Any time

For an 8 fl oz cup of decaf coffee, average clearance (half-life 5 h), 8 hours of sleep. "Any time" means even one at bedtime stays under the line.

How long it lasts

The caffeine from an 8 fl oz cup of decaf coffee peaks in your blood about 75 minutes after you start it, at roughly 6.8 mg. Half of it is gone in about 5 hours for an average adult; that ranges from roughly 3 to 7 hours, and longer in pregnancy or with some medicines.

Time after	3 hours	6 hours	9 hours	12 hours
Still in you	5.6 mg	3.7 mg	2.4 mg	1.6 mg

So one had at 3 pm leaves about 2.8 mg at 11 pm. How long caffeine lasts explains the curve.

How it compares

Decaf coffee is stronger than 0% of the 22 coffees made at home we track, by caffeine per serving.

Per fluid ounce (1.0 mg) it is stronger than 0% of them.

To reach 400 mg in a day you would need about 50 of these.

More caffeine

Nescafé Decaf Instant Coffee 15 mg, 12 fl oz cup
RYZE Mushroom Coffee 48 mg, 1 cup, medium roast
illy Espresso 60 mg, 1 shot

FAQ

Is decaf coffee high in caffeine?

No, it is low. An 8 fl oz cup of decaf coffee has 2 to 15 mg, which is 8% of the 95 mg in an 8 fl oz cup of brewed coffee.

Can I drink decaf coffee at night?

For most people, yes: even late in the evening an 8 fl oz cup of decaf coffee stays under 50 mg at an 11 pm bedtime.

How long does the caffeine in decaf coffee last?

It peaks about 75 minutes after you start it. Of the 2 to 15 mg, about 3.7 mg is still in you 6 hours later and 1.6 mg after 12 hours, for an average adult with a 5-hour half-life.

Does decaf coffee have more caffeine than Red Bull?

No. An 8 fl oz cup of decaf coffee has 2 to 15 mg; an 8.4 fl oz can of Red Bull has 80 mg.

Method and limits

The caffeine figure comes from USDA FoodData Central; recipes, brewing and batches vary, so a real serving can differ. The curves use a standard one-compartment model with an average 5-hour half-life and a sleep-friendly line of 50 mg; your own body may clear caffeine faster or slower. How it works has the details.

These are estimates for information, not medical advice.