Around 200 mg per 16 oz
A 16 oz cold brew has roughly 200 mg of caffeine — often about double a same-size hot coffee. It ranges widely, from about 150 to 250 mg depending on brand and strength, and concentrates can be higher still. It tops the caffeine chart for a reason. (Typical averages; cold brew strength varies a lot.)
Why it's so strong
- High coffee-to-water ratio — cold brew uses far more grounds than drip.
- Long steep — 12–24 hours of contact pulls out more caffeine.
- Concentrates — many ready-to-drink cold brews are concentrated and meant to be diluted; drink them neat and the dose climbs.
The cold water makes it smoother and less acidic, which hides just how much caffeine is in there — that's the trap.
Mind your daily total
One large cold brew can be half of an adult's whole daily limit (400 mg) in a single drink. Add a second coffee and you're at the ceiling fast. If you love cold brew, make it your one caffeinated drink for the day.
And your sleep
Because the dose is so high, cold brew lingers. An afternoon one can leave a real amount of caffeine in your system at bedtime — exactly the kind of hidden sleep-thief the half-life calculator is built to catch.
Put it into practice: a 200 mg cold brew at 2 pm — is it gone by bed? Check with the half-life calculator.