As a coffee enthusiast, I’m excited to share that the Harvard T.H. Chan School of Public Health states that enjoying a moderate amount of caffeine (50-300 mg) can boost alertness, energy, and concentration. However, it’s worth noting that too much caffeine can lead to anxiety, restlessness, insomnia, and an increased heart rate[1]. Thankfully, drinking 2-5 cups of coffee per day is connected to a reduced risk of type 2 diabetes, heart disease, and liver and endometrial cancers[2]. Plus, savoring one to two cups daily might even help prevent heart failure[3].

The Dietary Guidelines for Americans suggest that a moderate coffee intake typically ranges from 3-5 cups daily, which is equivalent to around 400 mg of caffeine[4]. By limiting consumption to four or five 8-ounce cups of coffee per day—about 400 milligrams of caffeine—individuals can enjoy the health advantages of coffee while minimizing the risk of caffeine-related side effects such as anxiety and nervousness[5]. For the majority of healthy adults, up to 400 milligrams (mg) of caffeine per day seems to be a safe amount[6].

Caffeine content in a cup of coffee can differ based on the coffee type and serving size. Brewed caffeinated coffee typically contains around 65 to 175 milligrams (mg) of caffeine per cup, with larger servings potentially having up to 450mg of caffeine[7]. Although espresso has approximately double the caffeine concentration of brewed coffee, it is usually consumed in smaller amounts[7]. The Mayo Clinic states that a daily intake of up to 400 milligrams (mg) of caffeine is considered safe for most healthy adults, which is roughly equivalent to four cups of brewed coffee[8][9][10]. Nonetheless, individual sensitivity to caffeine can vary, and those experiencing headaches, restlessness, or anxiety may need to reassess their caffeine consumption[9]. Pregnant women or those trying to conceive are advised to limit their caffeine intake[9].

That being said, it’s crucial not to overdo it. The Mayo Clinic warns that consuming more than 4 cups of coffee per day can result in headaches, insomnia, nervousness, irritability, frequent urination or loss of bladder control, and a rapid heartbeat[11]. Ingesting extremely high amounts of caffeine (1,000 mg or more daily) can cause nervousness and jitters in most people[12]. So, for those of us who love our daily coffee ritual, it’s essential to keep an eye on our intake and avoid going overboard.