How Much Caffeine Should You Have In A Day?

While there’s nothing wrong with reaching for the coffee pot for a pick-me-up, regularly consuming too much caffeine can pose problems too.

For example, symptoms of an excessive daily caffeine intake include trouble sleeping, nausea, and increased feelings of anxiety. What’s more, suddenly quitting caffeine can result in caffeine headaches and difficulties concentrating.

But how much caffeine per day is too much? And how long does caffeine withdrawal last? In this article, we’ll talk through everything you need to know about your daily caffeine intake.

How much caffeine should I have in a day?

Whether it’s tea, coffee, carbonated soft drinks, or even chocolate, a lot of foods and drinks we consume contain caffeine. And while some caffeine is completely safe, there is a limit.

Typically, it’s best to limit how much caffeine you have in a day to around 400mg. However, if you’re pregnant, the recommended daily caffeine intake cuts down to 200mg per day.

In terms of how this limit translates, 400mg is about four or five cups of coffee a day, while 200mg equals around one to two cups. And when it comes to energy drinks, it’s best to avoid where possible, drinking no more than one per day if you do want to have one. But if you’re pregnant or breastfeeding, you should avoid them completely.

Don’t worry, consuming slightly more than your recommended daily caffeine intake is generally safe. However, regular excessive caffeine consumption can cause high blood pressure and digestive issues, as well as mental health issues, such as increased anxiety.

To help keep track of how much caffeine you have in a day, use our helpful table, below, as a rough guide to your daily caffeine intake:

You can also check the label of most store-bought caffeine drinks to check their exact caffeine levels. When keeping track of how much caffeine you have in a day, also consider that some foods contain caffeine too, such as dark chocolate or coffee flavoured ice cream.

How long does it take for caffeine to kick in?

People typically consume caffeinated drinks to boost their energy levels. However, the time it takes for the caffeine to kick in can vary from person to person.

On average, people will feel the immediate effects of caffeine between 5 to 30 minutes after consumption. These symptoms include increased alertness, faster heart rate, feeling more physically energised, and breathing quickly.

However, the effects of caffeine usually reach their peak at the 45 to 60 minute mark, which is when you’re likely to notice the coffee ‘jitters’. As coffee is a stimulant, it increases the activity in your nervous system, as well as the circulation of stress hormones cortisol and adrenaline. As a result, you may start to feel shaky, and your hands might tremble slightly.

But don’t worry, coffee ‘jitters’ are not generally a cause for concern, and they should stop as the caffeine leaves your system. Try sipping on some water or practising breathing exercises to help alleviate any jitters or shaky hands.

​How long does coffee stay in your system?

The more immediate effects of caffeine will typically start to dwindle after about an hour, but the caffeine itself actually stays in your system for much longer.

No matter how much caffeine you’ve consumed, you’ll still have half of that caffeine in your system after six hours. In fact, it can take up to 10 hours to completely clear your system of caffeine.

For example, if you drink coffee as a late afternoon pick-me-up, you’ll still have a significant amount of caffeine in your system at 10pm. It’s typically advised to avoid drinking caffeinated beverages at least eight hours before going to bed.

How long does caffeine withdrawal last?

Caffeine withdrawal symptoms can occur just a couple hours after it has left your system, but how long does caffeine withdrawal last?

Typically, you’ll start to notice symptoms of caffeine withdrawal around 12 to 24 hours after caffeine consumption. This usually peaks at around 50 hours, and the symptoms can last between two to nine days. The symptoms of caffeine withdrawal include:

• Headache.
• Increased feeling of anxiety.
• Irritability.
• Fatigue.
• Low energy.
• Nausea.

To help alleviate these symptoms, try to gradually reduce your daily caffeine intake, drink plenty of water, and improve your sleep quality. You can also take over the counter pain relief, such as paracetamol and ibuprofen, to manage headaches from caffeine withdrawal.

How can I reduce my caffeine intake?

If you suffer from a caffeine sensitivity or are struggling with a reliance on caffeine consumption, then it may be a good idea to reduce your daily caffeine intake.

While giving up caffeine may incur some symptoms of caffeine withdrawal, there are a few ways you can safely begin drinking less caffeine in the day.

1. Trade in caffeinated for decaf

If you simply just enjoy the taste of tea and coffee, then there are alternatives to help you give up caffeine, while still allowing you to enjoy the flavour of these beverages.

For example, you can try trading in your typical coffee or tea for decaf options. While decaf drinks still contain caffeine, it is a significantly lower amount. A cup of decaf coffee contains around 2mg to 15mg of caffeine, in comparison to regular coffee, which is typically over 100mg per cup.

However, if you’re more of a tea drinker, you can switch from black tea to herbal teas to cut out caffeine completely. You can find several herbal teas that contain no caffeine at all, with popular examples including chamomile tea, ginger tea, and peppermint tea.

2. Gradually reduce your intake

Giving up caffeine abruptly is not advised – instead, it’s best to gradually reduce your daily caffeine intake over time.

You can try drinking one less cup of tea or coffee a day to slowly reduce your intake. Alternatively, you can stop drinking caffeine during the later hours of the day. If you usually have a late afternoon coffee to see you through the last portion of the day, try gradually working up to cutting out caffeine an hour earlier each day.

3. Regularly drink water

Essential for keeping you healthy and hydrated, regularly drinking water is also a great way to reduce your daily caffeine intake and help stave off any painful withdrawal symptoms as well.

While tea and coffee do count towards your daily water intake, if you’re looking to reduce the amount of caffeine you drink, replacing this with water will keep you hydrated. Additionally, drinking water may help alleviate caffeine withdrawal symptoms, such as headaches and nausea.

Drinking caffeine in reasonable amounts is quite safe and any adverse effects typically wear off once the caffeine has left your system. If you’re looking for more ways to manage high blood pressure or boost energy levels through your diet, head over to our Be Healthy hub for more helpful content.

Medically reviewed by Cheryl Lythgoe on May 2024.