Social Jetlag Calculator
Measure how far your weekend sleep midpoint shifts from your weekday schedule.
Your result
Social jetlag is the gap between your body clock on work days and free days. Over an hour is linked to tiredness and poorer health; keeping wake times more consistent helps.
Medical disclaimer: This tool is for education and is not medical advice. Read more.
Search by intent
Find this tool when you want to:
Learn more
Sleep Cycles and How to Wake Up Refreshed
Why timing your alarm around 90-minute cycles can help.
Sleep & Mental WellbeingHow Much Sleep Do Adults Need?
Seven to nine hours for most adults, and the cost of shortchanging it.
Sleep & Mental WellbeingCaffeine and Sleep: When to Stop
Caffeine lingers in the body longer than most people think.
Frequently asked questions
What does the Social Jetlag Calculator do?
Measure how far your weekend sleep midpoint shifts from your weekday schedule. Enter your values and the result and chart update instantly.
How accurate is it?
It uses published, widely used formulas. Results are estimates for education and planning, not a diagnosis. Talk to a qualified clinician about decisions affecting your health.
Is my information stored or shared?
No. All calculations run in your browser and nothing you type is sent to a server or saved.
What can I search to find this tool?
People find it by searching for: weekend sleep shift; social jet lag; weekday vs weekend sleep.