Caffeine can be very helpful, or even necessary, until it isn’t. For so many people, a morning cup of coffee makes a busy, obligation-packed day feel possible. But caffeine later in the day can also make it harder to fall asleep, stay asleep, or wake up feeling rested. Then you need more coffee the next day, and the cycle continues.

Of course, coffee gets most of the blame, but it is not the only late-day source of caffeine that can affect your sleep. To get clearer guidance, we asked sleep experts point-blank when most people should stop drinking caffeine. They also explain why the “right” cutoff can vary, and what you need to consider when making your decision.

The Best Time of Day to Stop Drinking Caffeine

We all know caffeine can keep you up, but the bigger question is how early you actually need to cut it off. “Caffeine too close to bedtime can have a wide range of effects—it can reduce how long it takes to fall asleep, reduce the quality of sleep, and disrupt your sleep architecture,” says Tom Chambers, MBBS, sleep medicine doctor and co-founder of Theta Sleep.1 Despite the well-known negative consequences, that does not mean everyone needs the same hard stop. The best time to stop drinking caffeine depends on your bedtime, your typical caffeine dose, and how quickly your body breaks the substance down.

Consider Your Bedtime

Instead of choosing one set-in-stone time, Chambers first suggests basing your caffeine cutoff on when you plan to go to bed that day. “We often tell people to ‘avoid caffeine after lunchtime,’ which is a bit of a ‘one-size-fits-all solution’ and rarely works in practice,” says Dr. Chambers. “We should definitely think about it based on our bedtime rather than a set time of the day. If you’re someone (like me) who’s in bed at 9 p.m., then you want to stop caffeine much earlier than someone in bed at midnight!”

Evaluate Your Caffeine Metabolism

You also want to think about how quickly your body clears caffeine. According to recent research, caffeine has an average half-life of three to seven hours in healthy adults, but that varies considerably.2

“We have some folks that metabolize (break down) caffeine very slowly, and they should be spacing their caffeine intake even further from bedtime,” says Andrew Valenzuela, MD, board-certified sleep medicine specialist and medical director at Sleep Cycle Center. “The golden rule is to set a caffeine cutoff at least eight to 10 hours before your target bedtime.” That range should account for slower caffeine metabolism and the fact that caffeine can linger in your system, even if you don’t feel wired.

Think About the Dose

Lastly, dose matters. In general, it can take a substantial amount of caffeine to significantly disrupt sleep, but timing still matters. Dr. Valenzuela cites one study published in the Journal of Clinical Sleep Medicine that found that 400 milligrams of caffeine—a whopping 4 cups of coffee—reduced total sleep time by more than one hour when consumed six hours before bed. If you go to bed at 10 p.m., that means drinking a lot of caffeine as late as 4 p.m. could have a real effect on your sleep and subsequent energy levels. 3

Another study showed the cutoff may need to be even earlier when the caffeine dose is that high. “More recent clinical trials in sleep medicine show that high doses within eight to 12 hours of bedtime significantly increase sleep fragmentation and delay sleep onset,” Dr. Valenzuela adds. In one randomized crossover trial, 400 milligrams of caffeine affected sleep even when taken 12 hours before bed. That means you’d need to stop drinking that much caffeine by 10 a.m. if your target bedtime is 10 p.m.1

Before you panic, that doesn’t mean every small cup of coffee past noon will ruin your sleep. In that same trial, 100 milligrams of caffeine did not significantly affect sleep at any time point tested. So the main takeaway here is timing and dose: A small amount may not disrupt sleep for everyone, but a larger dose can still interfere even when you drink it much earlier in the day.

Other Beverages Besides Coffee to Limit in the Evening

To make matters a little more confusing, we’re told not all caffeinated beverages act the same way when it comes to sleep. “There are lots of variables to consider, including volume, concentration, sugar content, and added active ingredients,” says Dr. Valenzuela, who calls out pre-workout drinks as the highest risk. “A single scoop can contain 200 milligrams to 400 milligrams of caffeine (equivalent to 2 to 4 cups of coffee), often combined with stimulants like yohimbine or taurine,” he says. “Taking pre-workout drinks for a 5:30 PM gym session is a recipe for nighttime insomnia.”

Other culprits include popular energy drinks and shots. “Beyond having 150 milligrams to 300 milligrams of caffeine (if not more!), high sugar levels can cause a blood sugar spike and crash, triggering cortisol spikes that wake you up in the middle of the night,” Dr. Valenzuela says.

Soda and green tea have a lower caffeine content, but drinking an excessive amount at dinner or later can “trickle caffeine into your system right before bed,” Dr. Valenzuela warns. Matcha has even more caffeine at about 70 milligrams per serving, depending on the brand and how it’s prepared.

“The best advice is to check the product,” says Dr. Chambers. “Tea is probably the most confusing; many teas are naturally decaffeinated, but others are very high in caffeine—particularly green tea. I’ve had many patients drinking cup after cup of green tea in the evening without knowing this!”