Memento Mori Calendar: Visualise Your Life in Weeks
This memento mori calendar displays your entire life as a grid of weeks — approximately 4,000 cells representing a typical human lifespan. Each filled cell is a week you have already lived. The glowing cell is now. The empty cells are what remains. The concept of memento mori — Latin for "remember that you will die" — has been practised since ancient Rome as a philosophical tool for living deliberately.
How to Calculate Life Expectancy Using ONS Life Tables
This tool calculates personalised life expectancy using the actuarial life table method with data from the Office for National Statistics (ONS) 2022-2024 UK National Life Tables. The ONS publishes mortality probabilities (qx) by single year of age from 0 to 100 for both males and females. Life expectancy at birth in the UK is currently 79.1 years for males and 83.0 years for females.
The calculation uses the proportional hazards adjustment: qx_adjusted = 1 - (1 - qx_baseline) ^ combinedHR. For each year of age from the person's current age to 100, the baseline probability of death is adjusted by a combined hazard ratio reflecting lifestyle factors. A survival curve is built from the adjusted probabilities, and remaining life expectancy is computed by summing person-years lived across all ages.
Peer-Reviewed Hazard Ratios for Lifestyle Risk Factors
Smoking and Mortality
Smoking hazard ratios from Jha et al., NEJM Evidence 2024 (1.48 million adults, 122,697 deaths across US, UK, Norway and Canada cohorts): current smokers vs never-smokers HR 2.7-2.8; former smokers vs never-smokers HR 1.3. Adjusted for age, education, alcohol and obesity. Smoking is the single largest modifiable risk factor for all-cause mortality.
BMI and Mortality
BMI hazard ratios from Global BMI Mortality Collaboration, Lancet 2016 (3.95 million never-smokers, 385,879 deaths, 189 studies). Reference category BMI 22.5-25. Underweight (BMI below 18.5) HR 1.82; overweight (BMI 25-30) HR 1.07-1.20; obese class I (BMI 30-35) HR 1.49; obese class II (BMI 35-40) HR 1.95; obese class III (BMI 40+) HR 2.76.
Physical Activity and Mortality
Physical activity hazard ratios from Arem et al., JAMA Internal Medicine 2015 (661,137 adults, 116,686 deaths, NCI Consortium). Reference: inactive. Meeting guidelines of 150 minutes moderate activity per week HR 0.69; two to three times guidelines HR 0.63; three to five times guidelines HR 0.61. Maximum mortality benefit plateaus at approximately three times the minimum recommendation.
Alcohol and Mortality
Alcohol consumption hazard ratios from Zhao et al., JAMA Network Open 2023 (4.84 million participants, 425,564 deaths, 107 cohort studies). After adjustment for abstainer biases, low-volume drinking showed no significant mortality benefit (RR 0.97, CI 0.88-1.07). Heavy drinking of 65g per day or more: HR 1.34 for men, HR 1.61 for women versus lifetime abstainers.
Diet Quality and Mortality
Diet quality hazard ratios from Schwingshackl et al., Advances in Nutrition 2019 (1.68 million participants, 221,603 deaths). High versus low Mediterranean diet adherence: HR 0.77-0.82. Wang et al., Circulation 2021 (1.89 million participants): five versus two fruit-and-vegetable servings per day HR 0.87. Good diet quality is associated with approximately 20% reduction in all-cause mortality risk.
Sleep Duration and Mortality
Sleep duration hazard ratios from GeroScience 2025 meta-analysis (79 cohort studies). Reference: 7-8 hours. Short sleep of less than 7 hours HR 1.14; long sleep of 9 hours or more HR 1.34. Both short and long sleep durations are associated with increased mortality risk compared to the optimal 7-8 hour range.
How Many Weeks Are in a Human Life?
A human life of 77 years contains 4,004 weeks. UK male life expectancy of 79.1 years equals 4,113 weeks. UK female life expectancy of 83.0 years equals 4,316 weeks. With all optimal lifestyle factors — never smoking, normal BMI, very active, moderate alcohol, good diet, 7-8 hours sleep — a 30-year-old male can expect approximately 87 years (4,524 weeks). A high-risk profile may yield approximately 64 years (3,328 weeks). Each week is precious and finite.
Life Expectancy Calculation Methodology
The life table plus hazard ratio approach is the standard actuarial-epidemiological technique used by professional life expectancy calculators including the myLongevity calculator from the University of East Anglia and Institute and Faculty of Actuaries, Project Big Life tools from the Ottawa Hospital Research Institute, and the methodology described in Strauss, Vachon and Shavelle (2005) in the Journal of Insurance Medicine.
The combined hazard ratio is the product of individual lifestyle factor hazard ratios, capped at a maximum of 5.0 to prevent overestimation. This cap is informed by Li et al. (Circulation 2018) who found that having all five low-risk lifestyle factors versus none gave an all-cause mortality HR of 0.26, implying a combined HR of approximately 3.8 for the worst-case profile.
The ONS 2022-2024 National Life Tables contain 101 qx values per sex (ages 0 to 100), released December 2025. These period life tables are based on population estimates, births and deaths averaged over three consecutive years 2022, 2023 and 2024 for the United Kingdom.
About This Memento Mori Tool
How Will You Spend It is a free, open-source memento mori calendar and life expectancy calculator. All calculations run entirely in the browser with no server dependency. Your data is stored only in your browser's local storage and is never transmitted. The tool is built with vanilla HTML, CSS and JavaScript. Created by Oliver Gooding.