Question 1

How much caffeine is safe per day?

Accepted Answer

The FDA recommends up to 400 mg of caffeine per day for healthy adults — about 4 cups of brewed coffee. Pregnant women should limit intake to 200 mg, and teens should stay under 100 mg/day. Individual tolerance varies based on body weight, age, medications, and sensitivity.

Question 2

How is the safe caffeine limit calculated?

Accepted Answer

We use the standard 6 mg/kg of body weight guideline recommended by the European Food Safety Authority, then clamp it within the 100-400 mg range based on age (kids, teens, adults, pregnant) and lifestyle factors. The result is your personalized daily ceiling.

Question 3

Does decaf coffee contain caffeine?

Accepted Answer

Yes, but very little. An 8 oz (240 ml) decaf coffee typically contains 2-15 mg of caffeine compared to 80-120 mg in regular coffee. We default decaf to 5 mg per cup, but you can edit the value if needed.

Question 4

How long does caffeine stay in your system?

Accepted Answer

Caffeine has a half-life of about 5-6 hours in healthy adults, meaning half the caffeine is still active 6 hours after consumption. It can take 10+ hours to fully clear. This is why afternoon coffee can disrupt sleep even if you feel tired.