The Screen Time Cost Calculator
Screen time numbers are easy to shrug off — "4 hours" sounds like nothing. Spread over a year or the rest of your life, it stops sounding like nothing. Two sliders, honest math, no sign-up.
The assumptions, out in the open
A waking day is counted as 16 hours (assuming roughly 8 hours of sleep). The lifetime projection runs to age 80 and assumes your current daily average stays constant — real life won't be that neat, but it's the honest way to show what a habit costs if nothing changes. A book is counted as 8 hours of reading (a typical novel at an average reading speed). The language estimate uses roughly 700 hours of study, in line with the U.S. Foreign Service Institute's published estimates for reaching professional working proficiency in languages closely related to English, such as Spanish or French.
One thing this calculator deliberately doesn't claim: that all screen time is wasted. Some of your hours are work, connection, and things you'd choose again. The number worth staring at is the share that just happened to you — the reflexive, unchosen part. If you want to know where your time actually goes, your phone's built-in screen time report will tell you; if you want to change the reflexive part, that's what reducing screen time at the root is about.
Where your number comes from
If you don't know what to enter, check your phone: Settings → Screen Time on iOS, or Digital Wellbeing on Android. People's guesses are often far off, so the measured number is worth checking. For context on how your country compares, see our screen time by country reference — internet users worldwide average over 6 hours a day online.
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Frequently asked questions
How do I calculate my screen time?
Check your phone first: Settings then Screen Time on iOS, or Digital Wellbeing on Android gives you a daily average. Enter that number and your age in the calculator above to see what it adds up to over a year and a lifetime. People's guesses are often far off, so the measured number is worth checking.
How much of my life is spent on screens?
At 4 hours a day you spend about 25% of your waking hours on screens, which is roughly 61 full 24-hour days per year. The calculator works this out from a 16-hour waking day and projects it to age 80 at your current daily average.
Is 4 hours of screen time a day a lot?
It is below the 6 hours 38 minutes a day that internet users aged 16–64 spend online on average (DataReportal), but it still amounts to about a quarter of your waking hours. What matters more than the total is how much of it was reflexive rather than chosen - work and connection are not the same as unchosen scrolling.
What assumptions does this calculator make?
A waking day is counted as 16 hours, assuming roughly 8 hours of sleep. The lifetime projection runs to age 80 and assumes your current daily average stays constant. A book is counted as 8 hours of reading, and the language estimate uses roughly 700 hours of study, in line with the U.S. Foreign Service Institute's estimates for languages closely related to English.