SCREEN-TIME INVENTORY
Audit a week before setting a limit
This retrospective calculator helps adults, caregivers, students, and researchers turn category logs into one non-duplicated weekly total. It keeps required and optional classifications visible but does not treat either label as evidence of benefit or harm.
| Category line | Days | Minutes per day or deduction | Weekly minutes |
|---|
Detailed calculation process
Formula, declared symbols, substitutions, intermediate results, and reconciliation
R = 5Rw + 2Re; O = 5Ow + 2Oe; G = R + O; U = G − X; D = U/7
The page first expands four daily category averages into weekly device minutes. It then subtracts X minutes of verified simultaneous-device overlap once, producing U unique clock minutes and daily average D.
| Symbol | Meaning | Default | Unit |
|---|---|---|---|
| Rw, Re | Required weekday and weekend averages | 360, 60 | min/day |
| Ow, Oe | Optional weekday and weekend averages | 180, 300 | min/day |
| X | Concurrent-device overlap | 210 | min/week |
| G | Raw device-record total | calculated | min/week |
| U, D | Unique weekly and daily clock time | calculated | min/week; min/day |
Default substitution: R=5(360)+2(60)=1,920; O=5(180)+2(300)=1,500; G=3,420; U=3,420−210=3,210 minutes; D=3,210/7.
Six-step usage audit
Construct one consistent observation week
- Select a representative seven-day period and list every phone, tablet, computer, television, console, and shared device covered.
- Freeze the definitions of required and optional use before reviewing totals.
- Export or transcribe weekday values and calculate five-day averages.
- Repeat the calculation for the two weekend days instead of merging all seven days.
- Review timestamps to find genuine simultaneous-device intervals and enter that overlap once.
- Compare the unique total with the 168-hour week and investigate gaps or implausible records.
Five inventory fundamentals
Know what the ledger is—and is not—counting
Device minutes
Raw logs often sum time per device or application, so two active records can refer to the same clock interval.
Unique clock time
This is the weekly total after the entered overlap deduction; it cannot exceed raw device time.
Required category
A personal accounting label for use that must occur under current obligations or access needs.
Optional category
A planning label for use that may be changeable; it is not synonymous with harmful or valueless use.
Observation boundary
Devices, dates, time zones, and background-use rules must be stated so a later week can be compared fairly.
Three measurement deep dives
Resolve the errors hidden by a daily average
Foreground versus background
Music, navigation, ambient video, and locked-screen timers can inflate application totals without representing active attention. Document a consistent inclusion rule.
Shared-device blind spots
Television and classroom devices may not appear in personal dashboards. A diary can complement exports, but estimates should remain labeled.
Category ambiguity
A video call may serve work, care, friendship, or entertainment. Freeze the purpose rule instead of recategorizing it to improve the result.
Evidence quality
Keep the raw record behind the average
Save device exports, dashboard screenshots, diary intervals, the local date range, devices omitted, category definitions, and the exact overlap intervals deducted. Recalculate when an operating-system update changes how activity is measured.
Usage limitations
What a minute inventory cannot reveal
- Device dashboards use different rules for foreground, background, notification, browser, and cross-device activity.
- The page cannot infer attention, multitasking intensity, content quality, social context, learning value, or distress.
- Required and optional labels are user classifications, not clinical or ethical judgments.
- Overlap is entered as one weekly total and is not allocated back to required or optional categories.
- A representative week can fail to capture holidays, deadlines, travel, illness, exams, or seasonal changes.
Usage glossary
Six measurement terms
- Device minute
- One minute recorded by one included device or application.
- Concurrent use
- Two or more counted devices active during the same clock interval.
- Unique time
- Raw device time minus verified overlap.
- Foreground activity
- Use recognized by a system as the active application or screen.
- Category rule
- The declared method for assigning an interval to required or optional use.
- Observation week
- The exact seven-day window underlying the reported averages.
Two audit cases
A dual-screen worker and a shared-device household
Dual-screen evening
A laptop records a streamed program while a phone records social browsing for the same 45 minutes. The audit subtracts that interval once without erasing either category total.
Family television gap
Personal phones provide exact exports, but shared television time is diary-based. The report labels the source difference instead of pretending every input has equal precision.
Important note
Do not turn a descriptive total into a diagnosis
If use is associated with sleep loss, distress, loss of control, unsafe content, bullying, developmental concerns, or missed responsibilities, an accurate time total is only one piece of evidence. Seek appropriate professional or institutional support.
Usage questions
Frequently asked questions
Why subtract concurrent-device minutes?
Two devices used during the same clock interval create two device records but only one interval of lived time.
Is required screen time automatically good?
No. Required is an accounting category, not a judgment about content quality, safety, or health.
Can optional share exceed 100%?
Yes if overlap is removed from the unique-time denominator without assigning that overlap to a category; treat the share as a classification warning in that edge case.
What if the weekly total is zero?
The page reports zero hours and a zero optional share rather than dividing by zero.
Should background audio count?
Choose a rule before logging. Passive audio, navigation, and always-on displays can be excluded or tracked separately, but the rule must stay consistent.
Can this tell me whether my use is excessive?
No. It inventories time only and cannot determine a medical, developmental, occupational, or educational threshold.
Official context and follow-on decisions