Screen Time Calculator
Total your daily screen time and see what it adds up to across a year and a lifetime.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Screen time is easy to underestimate because it is spread across devices. This calculator totals the hours you enter and converts them to yearly hours and full 24-hour days. If you use devices at the same time, those overlapping hours may be counted more than once. The total is not a health assessment.
Worked example
calculated with the default values below
Phone hours per day 3 h · Computer hours per day 6 h · Television hours per day 2 h · Tablet hours per day 1 h · Share that is work or study 50 % · Waking hours per day 17 h Total screen time per day 12.00 h · Leisure screen time per day 6.00 h · Share of waking hours 70.6 % · Screen time per year 4,380 h · Full days per year 182.5 days
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
T = Σh_i; L = T×(1 − w÷100); S = T÷W×100; Y = 365T÷24
- T
- Total daily screen time (h)
- h_i
- Daily hours on each device
- w
- Work/study share (%)
- W
- Waking hours per day
- L
- Leisure screen time (h/day)
- S
- Screen time as share of waking hours (%)
- Y
- Full days per year
Device hours are summed as entered; simultaneous use can be double-counted. Yearly days = daily hours × 365 ÷ 24; waking share uses the entered waking-hours value.
Frequently asked questions
Can the total double-count simultaneous device use?
Yes. The calculator adds the hours entered for each device, so watching TV while using a phone can count as two device-hours. The result is a simple summary, not a health assessment.