Chai and coffee cut-off calculator
That 5 PM chai might still be with you at midnight. See how much caffeine is left at bedtime, and when to have your last cup.
Why the evening chai matters
Caffeine blocks adenosine, the chemical that builds up while you're awake and makes you sleepy. Your body clears it slowly. For an average adult, half of a dose is still active about five hours later. In some people that half-life stretches to seven or eight hours, and in pregnancy or with some medicines it gets longer still.
A study published in the Journal of Clinical Sleep Medicine gave people caffeine at bedtime, three hours before and six hours before. Even the six hour group lost about an hour of sleep, and most didn't notice. That's why we never suggest a cut-off later than six hours before bed.
How much caffeine is in Indian drinks?
| Drink | Typical caffeine |
|---|---|
| Cutting chai (60 to 80 ml) | 15 to 25 mg |
| Regular cup of chai (150 ml) | 30 to 50 mg |
| Strong masala or kadak chai | 45 to 65 mg |
| Green tea (1 cup) | 25 to 35 mg |
| Instant coffee (1 teaspoon) | 55 to 75 mg |
| South Indian filter coffee | 80 to 120 mg |
| Café cappuccino or latte | 100 to 150 mg |
| Energy drink (250 ml) | About 80 mg |
| Cola (300 ml) | 25 to 35 mg |
| Dark chocolate (40 g) | 20 to 30 mg |
Estimates. Actual caffeine varies widely with the tea or coffee blend, how long it brews and how much you use. If you know your drink's exact content, type it into the calculator.
Smart swaps for the evening
- Swap the 6 PM chai for haldi doodh, warm jeera water, or a herbal tea such as tulsi or chamomile (check the label, as some tulsi blends contain green tea).
- Make the evening chai weaker and smaller: a cutting chai has roughly half the caffeine of a full cup.
- Watch hidden caffeine: colas, iced teas, energy drinks, pre-workout powders and some pain-relief tablets.
- If you can't drop the evening cup, move it earlier by 30 minutes each week.
Questions people ask
What time should I stop drinking tea or coffee?
At least six hours before bed. For an 11 PM bedtime, that's 5 PM. If you drink strong coffee or are sensitive to caffeine, make it 2 PM.
Does chai have less caffeine than coffee?
Usually, yes. A cup of Indian chai has around 30 to 50 mg, against 80 to 120 mg for filter coffee or 100 mg plus for a café coffee. But three cups of chai add up to more than one coffee.
Can caffeine affect my sleep even if I fall asleep easily?
Yes. Caffeine reduces deep sleep and makes sleep lighter and more broken, even in people who fall asleep without trouble. You may wake up less refreshed without linking it to the evening cup.
How long does caffeine stay in your body?
Its half-life is about five hours on average, so after ten hours a quarter of it is still there. It can take a full day to clear completely.