What this calculator works out
It takes the daily average from your phone's Screen Time report and assumes it stays the same for the rest of your life. From that one number and your age it works out how many years your phone would take, what share of your waking hours that is, and what the same hours would add up to if they went somewhere else. Then it draws your life as a grid of weeks so you can see the size of it.
The point isn't to make you feel bad about a number. Screen Time tells you hours per day, and hours per day are easy to shrug off. The same hours over the rest of your life are harder to ignore.
The formula
- Years left = expected lifespan − your age.
- Phone hours = daily Screen Time × 365 × years left.
- Years on your phone = phone hours ÷ (24 × 365), which is the same as daily hours × years left ÷ 24. These are full 24-hour days.
- Share of waking hours = daily hours ÷ 16.
- One hour a day back = 1 × 365 × years left, in hours, then ÷ (24 × 365) for years.
A worked example
Someone who is 25, averages 4 h of Screen Time a day and keeps the default lifespan of 80 has 55 years left.
- Phone hours: 4 × 365 × 55 = 80,300 hours.
- Years on the phone: 80,300 ÷ 8,760 = 9.2 years.
- Share of waking hours: 4 ÷ 16 = 25%. In 16-hour waking years that's 13.8.
- Books: 80,300 ÷ 6 = 13,383. Languages: 80,300 ÷ 750 = 107. Full-time work years: 80,300 ÷ 2,080 = 38.6.
- Scrolling: 1,680 minutes a week ÷ 3 = 560 minutes, at 1 m a minute = 560 m a week, or 1.7 Eiffel Towers.
- One hour a day back: 365 × 55 = 20,075 hours, which is 2.3 years.
How we calculate, and where the numbers come from
Lifespan
The default is 80, a round number. US life expectancy at birth was 78.4 years in 2023, and people who had reached 65 had 19.5 more years on average (CDC, Mortality in the United States, 2023). If you're already an adult, your own expectancy is likely above the at-birth figure. Change the default if you have a better number.
Waking hours
We assume 8 hours of sleep, so 16 waking hours a day. If you sleep less, the share of your waking hours is a little smaller than shown.
Books
Adults reading English silently average about 238 words a minute for non-fiction and 260 for fiction, according to a meta-analysis of 190 studies (Brysbaert, 2019, Journal of Memory and Language). We use 250. For the book we assume 90,000 words, a full-length novel; shorter and longer books are common. That gives 6 hours a book.
Languages
The US Foreign Service Institute estimates 24 to 30 weeks, or 600 to 750 class hours, for an English speaker to reach professional working proficiency in languages close to English, such as Spanish, French, Italian and Portuguese (US Department of State, Foreign Language Training). We use the top of the range, 750 hours. FSI students also study on their own outside class, so treat this as a rough comparison.
Work years
A full-time year here is 40 hours a week for 52 weeks: 2,080 hours.
Scroll distance (an estimate)
Nobody measures this, so we built it from three assumptions and show each one: a third of phone time is spent scrolling a feed (the rest is messages, calls, video and so on), you swipe about 10 times a minute while scrolling, and each swipe moves the feed about 10 cm. That makes 1 m of feed per minute of scrolling. We compare it with the Eiffel Tower (330 m) and Mount Everest (8,849 m).
What it leaves out
It ignores leap days and assumes your daily average never changes, which it will. Screen Time also counts some time you'd count as useful: maps, calls, work messages. The result is what your current average adds up to, not a forecast.
Questions people ask
How much of my life will I spend on my phone?
Multiply your daily Screen Time by the years you have left, then divide by 24 to count it in full days. At 4 h a day from age 25 to 80, that's 9.2 years of round-the-clock phone, or 25% of your waking hours. The calculator on this page does it with your numbers.
How do I find my Screen Time on iPhone?
Open Settings, tap Screen Time, then See All App & Website Activity. Choose Week at the top and use the daily average it shows. The same screen lists the apps that took the most time.
How much screen time is normal?
There's no official daily limit for adults. For young children there is guidance: the World Health Organization's 2019 guidelines recommend no sedentary screen time for children under 2, and no more than one hour a day for ages 2 to 4. For adults, a more useful question is whether your number matches what you'd choose if you planned it.
Why does the calculator use 16 waking hours?
It assumes 8 hours of sleep, which leaves 16 waking hours a day. Phone time comes out of waking time, so the share of waking hours is the fairer comparison. The headline in years counts full 24-hour days, which keeps it on the low side.
Is the scroll distance real?
It's an estimate built on stated assumptions: a third of phone time spent scrolling a feed, 10 swipes a minute while scrolling, and about 10 cm of feed per swipe. The page shows the math, so you can redo it with your own numbers.
Do you store what I enter?
No. The math runs in your browser and there's no account. If you share your result, the numbers go in the link so it opens with them filled in, and the share image is drawn from that link each time. Nothing is saved on our side.
WHO guidance: Guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age (2019).