Screen Time Impact Calculator Formula

Understand the math behind the screen time impact calculator. Each variable explained with a worked example.

Use the Screen Time Impact Calculator

Formulas Used

Total Daily Screen Time

total_hours = total_screen

Health Impact Score

impact_score = min(total_screen * 5 + screen_before_bed, 100)

Recommended Break Interval

eye_break_interval = 20

Yearly Screen Time

yearly_hours = total_screen * 365

Variables

VariableDescriptionDefault
work_screen_hoursWork Screen Time(hours)8
leisure_screen_hoursLeisure Screen Time(hours)3
screen_before_bedScreen Use Before Bed15
total_screenDerived value= work_screen_hours + leisure_screen_hourscalculated

How It Works

Screen Time Health Impact

Impact Scoring

  • Each hour of screen time adds 5 points
  • Screen use before bed adds up to 15 points for sleep disruption

    • The 20-20-20 Rule

    Every 20 minutes, look at something 20 feet away for 20 seconds to reduce eye strain.

    Guidelines

    | Score | Impact | |---|---| | 0-30 | Low impact | | 31-55 | Moderate (use 20-20-20 rule) | | 56-75 | High (consider reducing) | | 76+ | Very high (take action) |

    Worked Example

    8 hours work + 3 hours leisure, screens until bedtime.

    work_screen_hours = 8leisure_screen_hours = 3screen_before_bed = 15
    1. 01Total screen time = 8 + 3 = 11 hours
    2. 02Impact score = 11 x 5 + 15 = 70 (High)
    3. 03Yearly hours = 11 x 365 = 4,015 hours

    Ready to run the numbers?

    Open Screen Time Impact Calculator