Screen Time Impact Calculator
Please note: This tool provides a general informational estimate only, not medical or psychological advice. If screen use is significantly affecting your wellbeing, consider speaking with a licensed mental health professional. If you are in crisis, call or text 988 (US Suicide & Crisis Lifeline) or your local emergency number.
Two Hours of Screen Time Is Not One Number
Total daily hours is the figure everyone quotes, but it's only half the story. Two hours spread across a working afternoon and two hours ending at midnight are not equivalent inputs to how you feel the next day — the timing carries weight of its own. This calculator takes both your daily total and how much of it lands close to bedtime, and combines them into a single informal reflection score.
The Formula
The calculator works from a general leisure screen-time reference point of 2 hours per day and a 30-minute allowance before bed. Two components are added, each individually capped, and the total is capped at 100:
Over Guideline = Daily Hours − 2.0
Hours component (only if Daily Hours > 2.0):
min((Daily Hours − 2.0) × 15, 60)
Bedtime component (only if Before-Bed Minutes > 30):
min((Before-Bed Minutes − 30) ÷ 5, 40)
Score = min(Hours component + Bedtime component, 100)
The weighting is worth reading carefully. Daily hours can contribute at most 60 points, reached at 6 hours per day. Pre-bed use can contribute at most 40 points, reached at 230 minutes. Neither component alone can max out the score — only the combination reaches 100.
How the Score Is Grouped
| Informal score | Label |
|---|---|
| Below 20 | Low likely impact |
| 20 to below 50 | Mild likely impact |
| 50 to below 75 | Moderate likely impact |
| 75 and above | High likely impact |
What the Hours Component Actually Produces
Each hour above the 2-hour reference adds 15 points until the 60-point cap is reached. These figures are computed directly from the formula above, with no pre-bed screen use included:
| Daily screen hours | Weekly hours | Hours over guideline | Score contribution | Resulting band |
|---|---|---|---|---|
| 1.0 | 7.0 | −1.0 | 0 | Low likely impact |
| 2.0 | 14.0 | 0.0 | 0 | Low likely impact |
| 3.0 | 21.0 | +1.0 | 15 | Low likely impact |
| 4.0 | 28.0 | +2.0 | 30 | Mild likely impact |
| 5.0 | 35.0 | +3.0 | 45 | Mild likely impact |
| 6.0 | 42.0 | +4.0 | 60 | Moderate likely impact |
| 8.0 | 56.0 | +6.0 | 60 (capped) | Moderate likely impact |
| 12.0 | 84.0 | +10.0 | 60 (capped) | Moderate likely impact |
All values computed by running this calculator's own formula. Note the cap's effect: past 6 hours a day, additional hours change nothing, and hours alone can never produce a "High" result. The 2.0-hour reference is a general wellness guideline for adult leisure screen time built into this tool, not a medical threshold or a personalised recommendation.
What the Bedtime Component Adds
Every 5 minutes of screen use beyond the first 30 before bed adds 1 point, up to 40. Combined with a fixed 4 hours of daily use (a 30-point contribution):
| Minutes before bed | Bedtime contribution | Total score | Band |
|---|---|---|---|
| 0 | 0 | 30.0 | Mild likely impact |
| 30 | 0 | 30.0 | Mild likely impact |
| 60 | 6.0 | 36.0 | Mild likely impact |
| 90 | 12.0 | 42.0 | Mild likely impact |
| 120 | 18.0 | 48.0 | Mild likely impact |
| 150 | 24.0 | 54.0 | Moderate likely impact |
| 230 | 40.0 | 70.0 | Moderate likely impact |
| 300 | 40.0 (capped) | 70.0 | Moderate likely impact |
Computed from the calculator's formula. Reaching the "High" band above requires both a high daily total and substantial pre-bed use — at 4 hours daily, no amount of evening screen time gets there.
Where This Is Genuinely Useful
- Making the weekly total concrete — 4 hours a day sounds unremarkable until it reads as 28 hours a week, which is most of a part-time job.
- Separating volume from timing — the two components show whether your number is driven by total use, evening use, or both.
- Testing a change before committing — re-running with a lower pre-bed figure shows what that specific change would and wouldn't move.
- Checking against your device's own report — most phones report screen time; entering the real figure rather than an estimate is usually the more sobering exercise.
How to Use This Calculator
- Enter your Average daily screen time (hours) — your phone or computer's built-in screen time report is a better source than memory. Accepts 0 to 24.
- Enter your Screen time within 1 hour of bed (minutes) — how much screen use typically falls in the hour before sleep. Accepts 0 to 600.
- Select Calculate to see your daily and weekly hours, how far you sit from the 2-hour reference, the informal score out of 100, and the band.
Related Calculations
Screen habits often show up in mood and stress ratings before anywhere else. The Mood Tracker Calculator summarises daily mood scores over time, and the Meditation Time Calculator totals up time spent on a deliberately screen-free practice.