How much caffeine is in your drinks?
Caffeine varies a lot between drinks. These are healthdirect's typical amounts:
| Drink | Typical caffeine |
|---|---|
| Espresso (50 mL cup) | 145 mg |
| Instant coffee (1 teaspoon) | 80 mg |
| Energy drink (250 mL can) | 80 mg |
| Black tea (220 mL cup) | 50 mg |
| Cola (375 mL can) | 36 mg |
| Milk chocolate (50 g bar) | 10 mg |
healthdirect says healthy adults can safely have around 400 mg a day, about 2 espressos, 4 instant coffees or 8 cups of black tea. If you're pregnant or breastfeeding, the advice is to keep to 200 mg a day. A café coffee with a double shot can use up much of that in one cup.
Signs it might be time to cut back
- You find it hard to have less. healthdirect notes that many regular coffee drinkers become dependent on caffeine.
- Your sleep is suffering. In one study, 400 mg of caffeine taken even six hours before bed noticeably disrupted sleep. An afternoon coffee can still be working at bedtime.
- You're having a lot. healthdirect links regular use of more than 600 mg a day with heartburn, insomnia, anxiety and other problems.
- You feel rough without it. A headache by mid-morning on days you skip coffee is a classic sign of withdrawal.
What caffeine withdrawal feels like, and how long it lasts
A review of 66 studies found the most reliable withdrawal symptoms are headache, tiredness, low energy, drowsiness, low mood, difficulty concentrating, irritability and feeling foggy. About half of the people in the experiments got a headache. Symptoms usually started 12 to 24 hours after the last dose, peaked at 20 to 51 hours and lasted 2 to 9 days. Even people stopping just 100 mg a day, a little more than one instant coffee, had symptoms.
The good news: withdrawal is temporary, and cutting back gradually makes it much milder.
A two-week plan to cut back
This is a simple approach based on healthdirect's advice to reduce slowly. Adjust it to how much you drink now.
- Days 1 to 3: count it. Log every coffee, tea, cola and energy drink for a few days. Most people underestimate.
- Days 4 to 7: drop one. Cut one caffeinated drink a day. Replace it with water, herbal tea or decaf, so the habit of the break stays.
- Set a cut-off time. Aim for no caffeine within six hours of bed. For most people that means nothing after early afternoon.
- Days 8 to 14: make it weaker. Try half-strength, a single shot instead of a double, or brew your tea for less time.
- Keep drinking water. Swapping coffee for water keeps your total fluids up while you cut back.
- Plan for a flat day. If a step down brings a headache or low energy, hold at that level for a few more days before cutting again.
Does coffee count towards your water?
Mostly, yes. A study that compared common drinks with water found coffee was retained about as well as water at the amount tested. So cutting back on caffeine isn't really about hydration. It's about sleep, energy and not depending on caffeine. Caffeine is still a mild diuretic, and swapping a coffee for water is an easy win. More in does coffee count as water?
How Hydration Hero helps
Hydration Hero is a water tracker built around habits:
- A quit-caffeine challenge gives you a clear goal and a streak to protect.
- The Coffee Buzz Meter tracks your daily caffeine and shows how it affects your hydration.
- Drinks are weighted by their real effect, so coffee doesn't count exactly like water, and your avatar gets a bit jittery when you've had a lot.
- Custom drinks let you log your decaf, herbal tea or half-strength latte accurately.
- Mate challenges let you cut back with a friend or your whole office.
On iPhone you can try it instantly as an App Clip. Not sure how much water you need? Use our water intake calculator.
Frequently asked questions
How much caffeine is too much?
healthdirect says healthy adults can safely have around 400 mg of caffeine a day, about 2 espressos, 4 instant coffees or 8 cups of black tea. If you're pregnant or breastfeeding, the advice is to limit caffeine to 200 mg a day.
How long does caffeine withdrawal last?
In a major review of the research, withdrawal symptoms usually started 12 to 24 hours after the last dose, peaked at 20 to 51 hours, and lasted 2 to 9 days. healthdirect says symptoms usually last up to a week, and can last longer if you drank a very large amount.
What's the best way to cut back on coffee?
Slowly. healthdirect suggests cutting back over time, for example one less caffeinated drink each day, and switching some drinks to decaf, weaker tea, herbal tea or water. Tapering makes withdrawal headaches less likely than stopping suddenly.
Does coffee dehydrate you?
Not much at normal amounts. In a study comparing common drinks with water, coffee was retained about as well as water at the amount tested. Caffeine is a mild diuretic, but at everyday amounts coffee still counts towards your fluids.
Can Hydration Hero help me cut down on caffeine?
Yes. Hydration Hero has a quit-caffeine challenge, and its Coffee Buzz Meter tracks your daily caffeine and shows how it affects your hydration. It also weights coffee by its real hydration effect, so your progress stays honest while you swap coffees for water.
Sources
- Caffeine, healthdirect
- A critical review of caffeine withdrawal (Juliano & Griffiths, 2004), Psychopharmacology
- Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed (Drake et al., 2013), Journal of Clinical Sleep Medicine
- Development of a beverage hydration index (Maughan et al., 2016), American Journal of Clinical Nutrition
- Hydration Hero: Water Reminder, App Store listing
Last updated 9 October 2026. General information, not medical advice. If you have a heart condition, anxiety, or are pregnant, talk to your doctor about caffeine. For information about caffeine in Australia, call the Alcohol and Drug Foundation's Drug Info and Advice Line on 1300 85 85 84.