How much caffeine is in Black Tea (8oz cup)?
中文：红茶（8 盎司）
Caffeine content
50 mg
Typical range: 40–70 mg
per 8 fl oz (237 ml)
About this drink
Black tea has more caffeine than green or oolong — roughly half a coffee. Variants like English Breakfast or Earl Grey are similar; Lapsang Souchong is slightly higher.
Ingredients: Black tea leaves, hot water
When will it clear your system?
50 mg with tannin-slowed absorption. A morning cup easily clears by afternoon; a 5pm cup may impact sleep for sensitive people.
Based on caffeine's 5-hour half-life, a Black Tea (8oz cup) consumed at 2:00 PM drops below the sleep-safe threshold (~20 mg) by approximately 20:37 the same evening.
Where this fits in a daily limit
That's about 25% of the 200 mg pregnancy guideline and 13% of the 400 mg general adult daily limit — comfortably moderate.
See our pregnancy caffeine guide or half-life sleep math for the deep dive.
How it compares
| Drink | Caffeine |
|---|---|
Black Tea (8oz cup) Generic | 50 mg |
| Green Tea (8oz cup) Generic | 35 mg |
| Oolong Tea (8oz cup) Generic | 45 mg |
Track your caffeine automatically
Snap a photo of any drink and SipNote logs it. See real-time caffeine on your Apple Watch with a "clear by HH:mm" forecast. $2.99 one-time, no subscription, no account.
Learn more about SipNoteFrequently asked questions
How much caffeine is in a Black Tea (8oz cup)?
A 8 fl oz (237 ml) Black Tea (8oz cup) contains approximately 50 mg of caffeine. Actual values may range from 40 to 70 mg depending on preparation and source variation.
Is Black Tea (8oz cup) safe during pregnancy?
The current ACOG and NHS guideline is under 200 mg of caffeine per day during pregnancy. A Black Tea (8oz cup) fits comfortably within that limit. Always consult your obstetrician for personalized advice.
When should I stop drinking Black Tea (8oz cup) for sleep?
Caffeine has a 5-hour half-life. To have under 20 mg circulating at bedtime (the typical sleep-safe threshold), stop drinking Black Tea (8oz cup) about 7 hours before sleep. 50 mg with tannin-slowed absorption. A morning cup easily clears by afternoon; a 5pm cup may impact sleep for sensitive people.
Black Tea (8oz cup) vs Green Tea (8oz cup) — which has more caffeine?
Black Tea (8oz cup) contains 50 mg per serving; Green Tea (8oz cup) contains 35 mg per 8 fl oz (237 ml). Black Tea (8oz cup) is the stronger of the two.
Does Black Tea (8oz cup) keep you awake?
50 mg is mild caffeine. Most people can drink Black Tea (8oz cup) in the afternoon without notable sleep impact.
Caffeine values shown are typical for the listed serving size. Actual content varies by preparation, brewing method, batch, and brand reformulation. Not medical advice — consult a healthcare provider for personalized guidance.