Coffee Caffeine Calculator
Estimate your caffeine intake from coffee and other drinks, then compare it with a general daily reference level.
Calculate your caffeine
95 mg
Estimated caffeine in this selection
How the caffeine calculator works
Select a drink, enter the serving size and choose how many servings you consumed. The calculator uses typical caffeine values to estimate your total intake. Actual caffeine content can vary widely by brand, bean type, roast, brewing method and serving size.
Typical caffeine amounts
| Drink | Typical serving | Estimated caffeine |
|---|---|---|
| Brewed coffee | 8 fl oz / 237 ml | About 95 mg |
| Espresso | 1 fl oz / 30 ml | About 63 mg |
| Instant coffee | 8 fl oz / 237 ml | About 62 mg |
| Decaf coffee | 8 fl oz / 237 ml | About 3 mg |
| Cold brew | 8 fl oz / 237 ml | About 150 mg |
| Black tea | 8 fl oz / 237 ml | About 47 mg |
| Green tea | 8 fl oz / 237 ml | About 28 mg |
| Energy drink | 8 fl oz / 237 ml | About 80 mg |
| Cola | 12 fl oz / 355 ml | About 34 mg |
What daily caffeine level should I use?
For most healthy adults, 400 mg per day is commonly used as a general reference level. During pregnancy, a lower reference of 200 mg per day is commonly used. Individual sensitivity varies, and some people may experience sleep problems, anxiety, palpitations or stomach discomfort at lower amounts.
Frequently asked questions
Does dark roast have more caffeine?
Not necessarily. Roast level alone does not determine caffeine content. Dose, bean type, grind size and brewing method usually make a larger practical difference.
Why is this only an estimate?
Caffeine varies between products and preparation methods. Product labels and manufacturer information are the best sources for a specific drink.
How long does caffeine stay in the body?
Caffeine often has an estimated half-life of roughly four to six hours in healthy adults, but metabolism varies.
Sources and Health Context
Caffeine quantities in coffee are estimates, not exact values for every cup. Actual amounts can vary according to the bean, serving size, dose, brewing method, extraction, and other preparation factors.
For most adults, the FDA cites 400 mg of caffeine per day as an amount not generally associated with negative effects, while noting that individual sensitivity varies. NHS pregnancy guidance limits caffeine consumption to 200 mg per day. The mean plasma half-life of caffeine in healthy individuals is about five hours, but substantial individual variation can occur.
This calculator is for informational and educational purposes only. It is not medical advice and does not diagnose conditions or prescribe caffeine intake. People who are pregnant, breastfeeding, have medical conditions, take medications that may interact with caffeine, or have unusual caffeine sensitivity should seek individualized guidance from an appropriate healthcare professional.