Caffeine in drinks
How much caffeine is in Iced tea (brewed, unsweetened)?
Data checked against the source on 2026-10-03 by Oleksii Y.
One Small drink (360 g) of Iced tea (brewed, unsweetened) has 72 mg of caffeine, according to USDA Agricultural Research Service, FoodData Central (FNDDS).
How Iced tea (brewed, unsweetened) compares
- Strength: 20 mg per 100 g.
- One Small drink (360 g) has as much caffeine as about three quarters of a cup of brewed coffee, which has 94.8 mg per 8 fl oz cup.
- Of the 17 other teas in our tea chart, 0 have more caffeine per serving and 17 have less.
How much will be left at bedtime?
1 × Small drink (360 g) of Iced tea (brewed, unsweetened)
Left at 11:00 PM (8 h later), average metabolism
≈ 24 mg
Range 11–36 mg (fast to slow metabolism)
To be at 50 mg or less by bedtime, have 72 mg by 7:37 PM (average) or 6:02 PM (slow metabolism).
What sleep studies found near this dose
- Gardiner et al. 2025 (randomized trial): In 23 healthy young men, 100 mg taken 12, 8 or 4 hours before bed had no significant effect on measured or self-rated sleep.
- Gardiner et al. 2023 (meta-analysis): To avoid losing sleep time, the authors suggest a coffee (107 mg per 250 ml) at least 8.8 hours before bed.
Estimate from a simple model: half-life of 3, 5 or 8 hours, 50 mg bedtime target. How we calculate
Caffeine by size
| Serving | Caffeine |
|---|---|
| Small drink (360 g) | 72 mg |
| Medium drink (495 g) | 99 mg |
How long does Iced tea (brewed, unsweetened) stay in your system?
Our model halves caffeine every 5 hours for average metabolism, and every 3 or 8 hours for fast or slow metabolism. From one Small drink (360 g) of Iced tea (brewed, unsweetened) (72 mg), about 36 mg is still in your body 5 hours later and about 18 mg after 10 hours. If you clear caffeine slowly (an 8-hour half-life), about 30 mg is left after 10 hours.
Estimated caffeine left at 11:00 PM from one Small drink (360 g) (72 mg), using a half-life of 5 hours for average metabolism and 3 to 8 hours for the range. How we calculate
| Had at | Left at bedtime (average) | Range |
|---|---|---|
| 8:00 AM (15 h before bed) | ≈ 9 mg | 2–20 mg |
| 12:00 PM (11 h before bed) | ≈ 16 mg | 6–28 mg |
| 3:00 PM (8 h before bed) | ≈ 24 mg | 11–36 mg |
| 6:00 PM (5 h before bed) | ≈ 36 mg | 23–47 mg |
How many fit in a day?
Reference amounts are for caffeine from all sources combined. Counted at the upper end of the stated amount, one serving at a time:
- Up to 400 mg a day for most healthy adults (FDA, EFSA): about 5 servings.
- Up to 200 mg at one time for healthy adults (EFSA): about 2 servings in one go.
- Up to 200 mg a day in pregnancy (EFSA, NHS): about 2 servings.
These are reference amounts for groups of people, not a personal limit. Some people feel jittery or sleep worse on much less. See the cutoff calculator for timing.
Good to know
USDA gives a separate weight of 23 g per fl oz for iced tea served with ice, against 30 g without, because ice takes up part of the cup.
How the serving amount was worked out: USDA lists 20 mg per 100 g; 360 g × 0.20 = 72.0 mg; 495 g × 0.20 = 99.0 mg.
Iced tea (brewed, unsweetened) vs other iced and bottled tea drinks
- Bottled black iced tea: Iced tea (brewed, unsweetened) has more caffeine than bottled black iced tea per 100 g (20 vs 11 mg). Iced tea (brewed, unsweetened): 72 mg per Small drink (360 g); Bottled black iced tea: 52 mg per 16 fl oz bottle (473 g).
- Lipton Iced Tea Lemon: Iced tea (brewed, unsweetened) has more caffeine than Lipton Iced Tea Lemon per typical serving. Iced tea (brewed, unsweetened): 72 mg per Small drink (360 g); Lipton Iced Tea Lemon: 21 mg per 16.9 fl oz bottle.
- Pure Leaf Sweet Tea: Iced tea (brewed, unsweetened) has more caffeine than Pure Leaf Sweet Tea per typical serving. Iced tea (brewed, unsweetened): 72 mg per Small drink (360 g); Pure Leaf Sweet Tea: 54 mg per 18.5 fl oz bottle.
Common questions
How much caffeine is in Iced tea (brewed, unsweetened)?
USDA Agricultural Research Service, FoodData Central (FNDDS) gives 72 mg of caffeine per Small drink (360 g). Other sizes are in the table on this page.
How many Iced tea (brewed, unsweetened) servings can I have in a day?
The FDA and EFSA cite up to 400 mg of caffeine a day, from all sources combined, for most healthy adults. At 72 mg per Small drink (360 g), that is about 5 servings if Iced tea (brewed, unsweetened) is your only source. In pregnancy the reference is 200 mg a day.
How late can I drink Iced tea (brewed, unsweetened)?
With an 11:00 PM bedtime, our model suggests having one serving by about 7:37 PM for average metabolism, or 6:02 PM if you clear caffeine slowly. This is an estimate, not a rule.
How long does Iced tea (brewed, unsweetened) stay in your system?
Of the 72 mg in one Small drink (360 g), roughly 36 mg remains after 5 hours and 18 mg after 10 hours with our average 5-hour half-life. From fast to slow metabolism, 10 hours later it is between 7 and 30 mg.
Where the number comes from
- Tea, iced, brewed, black, unsweetened. USDA Agricultural Research Service, FoodData Central (FNDDS). FDC ID 2710517, nutrient "Caffeine" (262): portions "1 small drink" = 360 g, "1 medium drink" = 495 g, "1 fl oz (with ice)" = 23 g. Accessed 2026-10-02. Source ↗
Recipes and labels change. If a number here no longer matches the label, the label wins.
General information, not medical advice
If you feel unwell after caffeine — for example chest pain, a fast or irregular heartbeat that does not settle, fainting, confusion or trouble breathing — get urgent medical help. If you are pregnant, take medication or have a heart, liver or anxiety condition, ask a doctor or pharmacist what amount is right for you.
Sources
- U.S. Food and Drug Administration (2024). Spilling the Beans: How Much Caffeine is Too Much? FDA Consumer Updates. fda.gov ↗
- European Food Safety Authority. Caffeine | EFSA. EFSA topic page (summary of the 2015 Scientific Opinion on the safety of caffeine). efsa.europa.eu ↗
- NHS. Foods to avoid in pregnancy. NHS. nhs.uk ↗
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