How much caffeine is in instant coffee?

An 8 fl oz cup of instant coffee has 62 mg of caffeine.

That's about three quarters of a cup of brewed coffee, and 16% 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 22 mg is still in you at an 11 pm bedtime. That should not affect most people’s sleep.

Bedtime

Add this to my day

Your whole day, every drink, in the free CaffeineIQ check. The iPhone app is coming soon.

Sizes

Size	Volume	Caffeine	mg per fl oz
8 fl oz cup shown above	8 fl oz (237 ml)	62 mg	7.8
1 tsp of powder		31 mg

Source: USDA FoodData Central · checked 10 Nov 2026

Latest time to drink it

For an 11 pm bedtime, most people should finish an 8 fl oz cup of instant coffee by about 9 pm. 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	1:55 pm	7 pm	Any time
10 pm	2:55 pm	8 pm	Any time
11 pm	3:55 pm	9 pm	Any time
Midnight	4:55 pm	10 pm	Any time
1 am	5:55 pm	11 pm	Any time

For an 8 fl oz cup of instant 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 instant coffee peaks in your blood about 75 minutes after you start it, at roughly 53 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	44 mg	29 mg	19 mg	13 mg

So one had at 3 pm leaves about 22 mg at 11 pm. How long caffeine lasts explains the curve.

How it compares

Instant coffee is stronger than 19% of the 22 coffees made at home we track, by caffeine per serving.

Per fluid ounce (7.8 mg) it is stronger than 22% of them.

To reach 400 mg in a day you would need about 6½ of these.

Less caffeine

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

More caffeine

Espresso 63 mg, Single shot
Iced Coffee 74 mg, 8 fl oz cup
Nespresso Original Espresso 50 to 100 mg, 1 espresso

FAQ

Is instant coffee high in caffeine?

It is moderate. An 8 fl oz cup of instant coffee has 62 mg, which is 65% of the 95 mg in an 8 fl oz cup of brewed coffee.

How much caffeine is in 1 tsp of powder of instant coffee?

1 tsp of powder of instant coffee has 31 mg of caffeine.

Can I drink instant coffee at night?

Earlier is better. Had at 7 pm, it leaves about 38 mg in an average adult at an 11 pm bedtime. The latest time for an 11 pm bedtime is about 9 pm.

How long does the caffeine in instant coffee last?

It peaks about 75 minutes after you start it. Of the 62 mg, about 29 mg is still in you 6 hours later and 13 mg after 12 hours, for an average adult with a 5-hour half-life.

Does instant coffee have more caffeine than Red Bull?

No. An 8 fl oz cup of instant coffee has 62 mg; an 8.4 fl oz can of Red Bull has 80 mg.

Method and limits

The caffeine figure comes from USDA FoodData Central and the other sources listed above; 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.