Free · Stanford & Karolinska Research-Based · No Sign-Up
🧬

Sleep Age Calculator

Discover your biological sleep age — is your brain aging faster or slower than your real age? Answer 6 questions based on Stanford, Karolinska & Nature 2025 sleep research.

Step 1 of 7 14%
Question 1 of 7
How old are you?
Your chronological age is used to calculate your sleep age gap.
🔬 The Science of Sleep Age
🧠
Stanford Sleep Age Discovery (2022)

Dr. Emmanuel Mignot’s team at Stanford analyzed 12,000+ sleep studies using machine learning to create a “sleep age” metric. They found people whose sleep age was older than their real age had significantly higher 10-year mortality risk — independent of all other health factors.

Mignot et al. (2022) npj Digital Medicine
📊
Karolinska Brain Aging Study (2025)

MRI brain scans of 27,500 people showed poor sleepers had brains appearing ~1 year older on average. The brain age gap widened by 6 months per 1-point drop in sleep quality score. Inflammation mediated ~10% of the effect.

Dove et al. (2025) eBioMedicine, Karolinska Institutet
⏱
The U-Shaped Sleep Duration Curve

A 2024 Nature study of US adults found an inverted U-shape: both short (<6 hrs) and long (>9 hrs) sleep add years to biological age. Short sleep adds up to 3.3 years; long sleep adds up to 2.7 years. Sweet spot: 6.4–7.8 hrs.

Huang et al. (2024) Scientific Reports; Sleep Chart (2025) eLife
🔁
Sleep Age Is Reversible

Unlike genetic age, sleep age responds to lifestyle changes within 4–6 weeks. Consistent 7–8 hr sleep reduced phenotypic age markers by up to 3.4 years in intervention studies. Exercise + sleep quality together = strongest anti-aging combination.

Walker (2017); Huang et al. (2024) Scientific Reports
Sleep Age GapGradeRisk LevelAction
−3 yrs or more youngerA+✅ ExcellentMaintain
0 to −2 yrs youngerA✅ GoodFine-tune
+1 to +3 yrs olderB/C⚠️ ModerateImprove now
+4 to +7 yrs olderD🚨 HighAct urgently
+8 yrs or more olderF🚨 SevereSee doctor
❓ FAQ
What is sleep age?
Sleep age is how old your brain appears biologically based on your sleep patterns — vs. your real age. Coined by Stanford’s Dr. Emmanuel Mignot using machine learning on 12,000+ sleep studies. A high sleep age predicts increased dementia, cardiovascular, and mortality risk. Source: Mignot et al. (2022).
Can poor sleep make you age faster?
Yes. The 2025 Karolinska study of 27,500 people found poor sleepers had brains appearing ~1 year older. Brain age gap widened 6 months per quality-point drop. Short sleep adds up to 3.3 biological years. Source: Dove et al. (2025); Huang et al. (2024).
What is a good sleep age score?
A sleep age equal to or below your real age is good. 2+ years younger = excellent (Grade A+). 1–3 years older = warning. 5+ years older = significant aging risk requiring action. Source: Mignot et al. (2022) npj Digital Medicine.
How much does sleep affect aging?
Sleep affects aging via 4 pathways: inflammation, telomere shortening, epigenetic changes, and hormonal disruption. Short sleep raises CRP inflammation by 40%, shortens telomeres, and reduces testosterone — all markers of accelerated aging. Source: Huang et al. (2024) Scientific Reports.
How can I reduce my sleep age?
Top 5 evidence-backed sleep age reducers: (1) Sleep 7–8 hrs nightly. (2) Consistent bedtime ±30 min. (3) No screens 60 min before bed. (4) Cut caffeine by 1 PM. (5) Exercise 150 min/week — reduces sleep age by up to 3 years. Source: Walker 2017; Karolinska 2025.
Is sleep age the same as brain age?
Related but different. Brain age uses MRI. Sleep age uses EEG sleep microstructure. Both are accelerated by poor sleep. This calculator uses validated self-report proxies (PSQI-based, UK Biobank protocol) as a non-invasive estimate. Source: Dove et al. (2025).
27,500
People Studied
+3.3
Bio Yrs (Short Sleep)
6m
Brain Age / Quality Point
4–6wk
To Reverse Sleep Age
👩‍⚕️
Medically Reviewed By
Dr. Sarah Mitchell, CCSH
Certified Clinical Sleep Health Specialist
Reviewed against Stanford (2022), Karolinska (2025) & PSQI protocols. Last updated March 2026.
Full Bio →

Fix Your Sleep Age — Use These Free Tools

Your sleep age is improvable. Start with the right bedtime and wake time — then track your progress.