Caffeine Calculator: Daily Intake Level
This caffeine calculator adds up the caffeine in everything you drink in a day, from brewed coffee and espresso shots to black tea, green tea, cola, energy drinks and dark chocolate, using typical US serving sizes. It compares your total with the FDA guide of about 400 mg a day for healthy adults, or lower limits for pregnancy and teens. Enter how many hours before bed you had your last caffeine and it estimates how much is still in your body at bedtime, using a 5-hour half-life. That helps explain poor sleep and plan a cut-off time.
Caffeine Calculator
Add up caffeine from coffee, tea, soda and energy drinks and see how much is left at bedtime.
How to use the Caffeine Calculator
- Enter how many servings of each drink you had today.
- Pick the guide that fits you: adult, pregnant or teen.
- Enter hours between your last caffeine and bedtime.
- Read your total, percent of the guide and bedtime level.
Caffeine half-life
Caffeine left = total × 0.5^(hours ÷ 5), using an average 5-hour half-life for healthy adults.
Features
- Typical US caffeine amounts
- Coffee, espresso, tea, soda, energy drinks
- FDA 400 mg adult guide
- Pregnancy and teen limits
- Bedtime caffeine left (half-life)
- Custom mg entry
Frequently asked questions
How much caffeine is too much?
The FDA says up to about 400 mg a day is not generally linked to harmful effects in healthy adults. That is roughly four 8 oz cups of brewed coffee.
How much caffeine is in a cup of coffee?
An 8 oz cup of brewed coffee has about 95 mg on average, but it can range from about 70 to 140 mg.
How long does caffeine stay in your body?
Caffeine has a half-life of about 5 hours in most adults, so half of it is still there 5 hours later.
How much caffeine is safe during pregnancy?
Many US health groups advise keeping it under 200 mg a day during pregnancy. Ask your doctor.
Should teens have caffeine?
Pediatric groups advise teens to limit caffeine to 100 mg a day or less and to avoid energy drinks.