How much caffeine is in a Dunkin' iced coffee? Dunkin' says a small (16 oz) Original Blend Iced Coffee has about 196 mg of caffeine, a medium (24 oz) about 294 mg and a large (32 oz) about 392 mg. That's roughly two, three and four 8 oz cups of brewed coffee, because Dunkin' brews its iced coffee at double strength before pouring it over ice.
A large is close to the FDA's 400 mg daily figure for adults on its own. And at an average 5-hour half-life, even a small takes almost 15 hours to fall below 25 mg. The caffeine calculator works out your own cutoff for any drink and bedtime.
Free toolCaffeine Cutoff CalculatorHow much caffeine is still in you at bedtime, and your latest cup.How much caffeine is in each size of Dunkin' iced coffee?
Dunkin' lists about 196 mg for a small, 294 mg for a medium and 392 mg for a large iced coffee. These figures are in the FAQ on Dunkin's Original Blend Iced Coffee page, checked in November 2026. Dunkin' notes they're approximate, based on its standard brewing and limited analytical data.
| Size | Volume | Caffeine (Dunkin's figure) | About the same as |
|---|---|---|---|
| Small | 16 fl oz | about 196 mg | two 8 oz cups of brewed coffee |
| Medium | 24 fl oz | about 294 mg | three cups |
| Large | 32 fl oz | about 392 mg | four cups |
That works out to about 12 mg per ounce of cup size at every size, so going up a size adds about 98 mg each time. The cup size, more than anything you add to it, sets your dose.
Why does Dunkin' iced coffee have so much caffeine?
Because it's brewed with twice the usual amount of coffee grounds. Dunkin' says it brews iced coffee fresh using twice the grounds, then pours the hot, extra-strength coffee over ice so it doesn't taste watered down. Twice the grounds means more caffeine per ounce of coffee, and the cups are big.
Milk, cream, sugar or a flavor swirl don't change the caffeine. They only change the taste and calories.
How much caffeine is in Dunkin' cold brew?
Dunkin' doesn't publish a caffeine figure on its cold brew page, so we can't give an official number by size. Dunkin' says its cold brew uses its Special Dark Roast blend steeped in cold water for 12 hours, and the cold brew nutrition panel lists calories but not caffeine.
Cold brew strength varies a lot with how it's brewed and diluted. For typical ranges and what drives them, see how much caffeine is in cold brew. If you want a number for your size at Dunkin', ask the store.
How much Dunkin' iced coffee caffeine is left at bedtime?
A small Dunkin' iced coffee at 2 PM still leaves about 56 mg in you at 11 PM, and a large leaves about 113 mg. The table uses the calculator's math: remaining caffeine = dose x 0.5^(hours / 5), for an 11 PM bedtime.
| Drink at | Small (196 mg) | Medium (294 mg) | Large (392 mg) |
|---|---|---|---|
| 8 AM | 25 mg | 37 mg | 49 mg |
| 10 AM | 32 mg | 48 mg | 65 mg |
| Noon | 43 mg | 64 mg | 85 mg |
| 2 PM | 56 mg | 84 mg | 113 mg |
| 4 PM | 74 mg | 111 mg | 149 mg |
| 6 PM | 98 mg | 147 mg | 196 mg |
This site uses about 25 mg at bedtime as a sensible ceiling. It isn't an official limit, just a useful line. A large iced coffee at 6 PM leaves as much caffeine at bedtime as a fresh small.
What's the latest time to drink a Dunkin' iced coffee?
For an 11 PM bedtime, finish a small Dunkin' iced coffee by about 8:09 AM. A medium or large can't fall below 25 mg by 11 PM unless you drink it before about 5 AM or 3 AM.
| Bedtime | Small (196 mg) | Medium (294 mg) | Large (392 mg) |
|---|---|---|---|
| 10:00 PM | 7:09 AM | 4:13 AM | 2:09 AM |
| 10:30 PM | 7:39 AM | 4:43 AM | 2:39 AM |
| 11:00 PM | 8:09 AM | 5:13 AM | 3:09 AM |
| Midnight | 9:09 AM | 6:13 AM | 4:09 AM |
In hours before bed, that's about 14 h 51 min for a small, 17 h 47 min for a medium and 19 h 51 min for a large. That doesn't mean a morning medium will ruin your night, but some caffeine will still be there at bedtime. In an at-home sleep study, a large caffeine dose taken 6 hours before bed cut total sleep by more than an hour.
Simple fixes: order a small, sip a large slowly across the morning and leave the rest, or switch to decaf after lunch. For evening coffee habits, see can you drink coffee at night.
How does Dunkin' iced coffee compare with energy drinks?
A small Dunkin' iced coffee (about 196 mg) has more caffeine than a 16 oz Red Bull (151 mg) or Monster (160 mg). A medium has about as much as a 300 mg energy drink, and a large has more than a 300 mg can of Bang.
| Drink | Caffeine |
|---|---|
| Brewed coffee, 8 oz | about 95 mg |
| Red Bull, 16 oz | 151 mg |
| Monster Energy, 16 oz | 160 mg |
| Dunkin' small iced coffee | about 196 mg |
| Dunkin' medium iced coffee | about 294 mg |
| Dunkin' large iced coffee | about 392 mg |
For more on the cans, see how much caffeine is in Red Bull and energy drinks and sleep.
How many Dunkin' iced coffees a day is too much?
For healthy adults, the FDA cites 400 mg of caffeine a day as an amount not generally linked to negative effects, and a large Dunkin' iced coffee alone is about 392 mg. Two smalls come to about 392 mg too. Any soda, tea or second coffee on top puts most people over.
If you're pregnant, breastfeeding, have a heart condition or take medications, talk to your health care provider about a lower limit. For a full daily tally, see how much caffeine is too much.