How Much Productive Time Do You Really Gain When You Multitask?

How much productivity can I potentially gain from multitasking? 

We all love the allure of multitasking – switching from reading a digital book, texting a peer, and working on a spreadsheet for our next presentation, all while meeting with our team via zoom. It is a cultural norm that drives our habits, our practices, and it as the heart of many of our “productivity” practices. Why work on only one thing when I can easily do 3-4 things at the same time! 

However, it doesn’t work.  

The answer to the question of “how much productive time do you gain?” is actually stated in negative terms – up to 40% of productivity loss depending on the complexity of the tasks you are attempting to do simultaneously. 

That’s right – you may just need to put your phone down for this one.  

Productivity is negatively impacted by multitasking – and not by a small percentage or only on selected tasks. Multitasking has many negative impacts, including that it: 

  • generates errors  
  • creates rework 
  • drives inefficiency  
  • slows throughput on each of the tasks attempted 
  • interferes with focus 
  • frustrates peers and teams 

What the research shows1 

Subtle “switching” costs cut efficiency, raise risk. 

Doing more than one task at a time, especially more than one complex task, takes a toll on productivity. Although that shouldn’t surprise anyone who has talked on the phone while checking e-mail or talked on a phone while driving, the extent of the problem might come as a shock.  

Psychologists who study what happens to cognition (mental processes) when people try to perform more than one task at a time have found that the mind and brain were not designed for heavy-duty multitasking. Psychologists tend to liken the job to choreography or air-traffic control, noting that in these operations, as in others, mental overload can result in catastrophe. 

Multitasking can take place when someone tries to perform two tasks simultaneously, switch from one task to another, or perform two or more tasks in rapid succession. To determine the costs of this kind of mental “juggling,” psychologists conduct task-switching experiments. By comparing how long it takes for people to get everything done, the psychologists can measure the cost in time for switching tasks. They also assess how different aspects of the tasks, such as complexity or familiarity, affect any extra time cost of switching. 

There appear to be two parts to the switch cost — one attributable to the time taken to adjust the mental control settings (which can be done in advance if there is time), and another part due to competition due to carry-over of the control settings from the previous trial (apparently immune to preparation). 

Surprisingly, it can be harder to switch to the more habitual of two tasks afforded by a stimulus. For example, Renata Meuter, PhD, and Alan Allport, PhD, reported in 1999 that if people had to name digits in their first or second language, depending on the color of the background, as one might expect they named digits in their second language slower than in their first when the language repeated. But they were slower in their first language when the language changed. 

What the research means 

According to Meyer, Evans, and Rubinstein, converging evidence suggests that the human “executive control” processes have two distinct, complementary stages. They call one stage “goal shifting” (“I want to do this now instead of that”) and the other stage “rule activation” (“I’m turning off the rules for that and turning on the rules for this”). Both stages help people to, without awareness, switch between tasks. That’s helpful. Problems arise only when switching costs conflict with environmental demands for productivity and safety. 

Although switching costs may be relatively small, sometimes just a few tenths of a second per switch, they can add up to large amounts when people switch repeatedly back and forth between tasks. Thus, multitasking may seem efficient on the surface but may take more time in the end and involve more error. Meyer has said that even brief mental blocks created by shifting between tasks can cost as much as 40 percent of someone’s productive time. 


Caroline Webb, in her book How to Have a Good Day, uses a word that the dictionary doesn’t like, but I really do – singletasking. Doing one thing at a time, doing it well, and then moving on to the next task. The level of discipline required to stay on task is high, but so is the reward. 

Webb describes the two systems (from Daniel Kahneman’s work in Thinking, Fast and Slow3) that our brains use to process all the information – the automatic (fast) system & the deliberate (slow) system. The two systems provide us with two different modes – one for analytical (deliberate), the other more instinctive (automatic). 

The deliberate system is amazing and is the one that we use to process complex tasks, but it comes with limitations: 

  • limited capacity – we can only reliably hold three to four “chunks” of information at a time 
  • sequential processing – while we can hold multiple items in our working memory, we can only process one item at a time – switching costs are incurred with every change in focus 
  • slow – compared to the automatic system, the deliberate system is dramatically slower and needs time to sort, translate, and analyze  
  • easily tires – without regular rest and refueling of our brain, we will react slower and make poor decisions 

The automatic system is responsible for processing those reflexive activities that we know, understand, and can be offloaded from our deliberate system – and give us the impression that we can multitask across a broad array of activities. 

The automatic system can process large amounts of data simultaneously – filtering, sorting, and alerting the deliberate system when a decision or analysis is necessary. So, yes, we can drive (automatic) and talk (deliberate) at the same time – until someone slams on their brakes or swerves into our lane. Then, driving takes over the deliberate system until the crisis is averted.  

Ever had this happen? I definitely have! What I normally say next is, “Sorry about that, now where were we?” … now where were we. The three or four things that I could hold and process in my deliberate system were the car in front of me, the two cars on either side of me, and the car that was probably a little too close to my back bumper. The conversation? Completely out the proverbial window!  

Maximizing Your Deliberate System 

There are a few very easy techniques that you can employ to simultaneously decrease distractions and increase your focused time during each day: 

  • Turn off notification sounds, vibrations, and pop-ups for emails, direct messages, and texts. Be intentional about when you go review and update emails, messages, and texts. 
  • An open-door policy doesn’t mean your door has to always be open (It simply means your team can come and talk to you about anything)! Close your door for those stretches of time where you need uninterrupted focus time. 
  • Schedule time on your calendar to complete the priority tasks you need to complete each day – you shouldn’t expect that time to manifest itself. 
  • Batch similar types of work into sections of your day.  
  • Deploy effective use of 17-minute sprints (from Michael Heppell’s book 17) – dedicated time to focus on task or project – no interruptions! Take a 3 to 5-minute break afterwards. If you run 4 or more sprints back-to-back, take a longer 15 to 30-minute break to refuel and refresh. 
  • Take advantage of how / when you do your best deep-thinking work – if you’re a morning person schedule blocks of complex work early in the day; if you need time to build momentum, schedule your heavy-thinking time later in the day.  

Don’t allow yourself to become enamored with the allure of multitasking – you may even feel busier than when singletasking – and you will think that you are moving lots of things forward. Busy-ness does not equate to effectiveness. Slow down, process one thing at a time – in the right way. The results may astound you. 

Do you want more time?

Answer a few simple questions to determine how much time you could gain each week for more focus, flexibility and freedom.