Let's assume you have a task at work that roughly should take one day to complete. Another assumption is that your work day is 8 hours long. How to measure how long did you actually work? We would need to count distractions. What could distract you or create a stop at your work flow:

• morning coffee/tea making
• breakfast
• trip to vending machine & snack
• trip to WC
• coffee/tea making
• searching for the perfect YT video as a background sound for your task
• somebody coming by your desk with the question
• somebody calling you with the question
• somebody messaging/hangouting you with the question
• somebody emailing you with the question
• lunch time
• thinking time
• visiting somebody's desk with the question
• calling somebody with the question
• messaging/hangouting somebody with the question
• emailing somebody with the question
• break time
• checking private email time
• checking private social media feeds time
• writing blog post about distractions at work time
• think about others

So these are distractions, how can you measure them. I came up with the genius idea. You find an 8h song or noise on YT, start playing it on your headphones once work started and pause it each time your work is interrupted. My today's choice was Tropical Island Beach Ambience Sound - 8 Hours Ocean Sounds For Relaxation And Holiday Feeling.

As you can imagine, you should be able to listen to the whole music/noise piece while working on the task, but I can guarantee you will be far from it. The played time will be your productive time, take away 8h and you'll have your distraction time. Bear in mind we do not calculate time requires by brain to be back on the task at full speed once distracted. Don't have an equation on hand. Yet.