Screen Time Impact Calculator

This digital-wellness calculator separates work and leisure screen exposure, adds them for a daily total, and multiplies that rounded total by seven for weekly hours. Work and leisure time affect those two totals symmetrically: one added hour has the same arithmetic effect in either field. The screen-to-outdoor ratio divides total screen hours by outdoor hours and rounds to one decimal. When outdoor time is zero, the engine substitutes 999 for any positive screen total rather than attempting division, so that value means “no outdoor denominator,” not a literal measured ratio. The Sleep Impact Score is driven mainly by minutes of screen use before bed. It takes discrete values of 0, 1, 3, 5, 7, or 9 at boundaries of any positive use, 30, 60, 90, and 120 minutes.

Leisure use above six hours adds one point, capped at 10. Work screen hours do not enter this score. Productivity Impact is a separate heuristic: leisure hours are multiplied by 1.2, outdoor hours subtract 0.5 each, and the result is constrained to 0–10. These outputs describe the calculator's chosen rules, not observed health effects for an individual. It does not account for screen brightness, content, breaks, device distance, work demands, exercise intensity, sleep schedule, chronotype, accessibility needs, or baseline health. In particular, “productivity” is an estimated index rather than measured job performance.