How long does a cup of coffee keep you awake?

Almost everyone says drinking coffee keeps you awake.

Most of us kickstart our day with a cup of joe but it doesn’t just end there. We tend to find ourselves reliant on coffee to keep us awake throughout the day, to get us through meetings, homework, assignments and especially during the dreaded sleep zone after lunch. Finally, your friends ask you out for supper but you’re just so tired, you might have that final cup for the day before you return home.

But how long does a cup of coffee actually keep you awake and focused on the task at hand? To better answer this widely asked but never answered question, we have to understand the various factors at hand.


Coffee contains caffeine, which after entering the body, increases your heart rate and blood pressure. This results in increasing energy levels and improving one’s mood.


Your body halves caffeine in around 5 hours. This means that for example, if I were to consume 63mg of caffeine (the amount caffeine in one espresso shot) now, I will have about 31mg of caffeine left in my body 5 hours later. After 15-45 minutes upon drinking coffee, the level of caffeine will peak in your bloodstream.


Depending on your body’s system, most people notice the burst of energy levels during this period of time. Some comment saying that they feel jittery and itchy at some body parts, while others feel no physical tweaks but report that they are better able to focus at the task at hand.

The duration of the effects of caffeine on your body depends on personal factors such as:

  • Age
  • Body weight
  • Sensitivity to caffeine
  • Smoking

If you are someone who consumes caffeine on a daily or regular basis, you might barely notice its effects. It becomes more of a habit for you to consume caffeine. But for someone who is very sensitive to it, the effects may be prolonged even till late in the night after consuming it in the day.

We at almighty believe that consumption should be kept regulated. If by drinking too many cups of coffee upsets your digestive system or prevents you from having a good night’s rest, then limit the number of cups you have per day.

One method that we find useful is to space out the dosage of caffeine. Try to have one in the morning, one in the afternoon and if really needed, one more in the evening. For our graveyard shift workers out there, try to have your last cup before sunrise. The moment you drink coffee with the sun up and blaring in your face, you might have difficulty trying to go to bed.

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