When communicating the scale of a crisis, it is common to look at a single daily snapshot. However, this fails to capture the true risk to a community over time. To find the real footprint of homelessness in the Royal Borough of Kingston upon Thames, we applied a dynamic statistical framework known as Age-Specific Incidence.

An Established Actuarial and Epidemiological Standard Our calculation does not rely on a newly invented formula. It is built on the exact same mathematical modelling used by global health and financial institutions to measure lifetime risk.

• Epidemiological Lifetime Risk Models: This is the identical framework used by major health charities, such as Cancer Research UK, to calculate their famous “1 in 2” statistic. By calculating the specific risk of an event occurring at every individual year of age, epidemiologists can sum those probabilities to find the total lifetime risk.
• Actuarial Life Tables: The insurance and pension industries use this age-weighted approach to calculate the probability of life events. Just as a life table does not apply an 80-year-old’s mortality risk to a 20-year-old, our model recognises that the risk of homelessness fluctuates wildly depending on age.
• Longitudinal Poverty Studies: Academic economists rely on age-specific cohort tracking to prove that temporary poverty is a widely shared experience, rather than a static condition affecting a tiny minority.

By adapting these gold-standard models to our verified local data, we have established a highly accurate baseline for the borough. Here is the transparent maths behind the calculation.

To calculate the lifetime risk for adults, we first defined the baseline local population. We took the official 2026 Kingston population projection of 175,600 and removed the child demographic (approximately 18%). Because KCAH works exclusively with single adults, this targeted filtering leaves a highly precise baseline adult population of roughly 143,992 residents.

Using our verified registration history between 2021 and 2026, we established a strictly deduplicated long-term average of 392 unique adult registrations per year.

While there were 2,112 total annual presentations logged across those five years, our database extraction deliberately isolates the exact number of different people. This confirms that exactly 1,960 unique individuals registered for support during this window. By dividing this total by five, we arrive at our baseline of 392. This mathematical safeguard actively removes repeat visitors from the equation, ensuring the final lifetime risk is never artificially inflated by individuals experiencing multiple overlapping crises.

Furthermore, our internal housing status data confirms that 94.4% of these recorded cases represent individuals experiencing actual homelessness, rough sleeping, sofa surfing, or actively threatened homelessness. This ensures our baseline strictly measures severe housing crises.

Homelessness risk is not spread evenly across a lifespan. Our intake data confirms that initial presentations are heavily front-loaded in early adulthood.

If we simply used a standard flat average across the whole population, we would artificially suppress the true lifetime risk. Instead, we modelled a statistical 18-year-old moving through every individual year of adulthood up to age 82. We calculated the specific registration probability for each year based on our real-world age curves.

By cumulatively summing the risk for each year of a standard adult lifespan, the model calculates a direct lifetime risk of 17.42%.

Mathematically, 17.42% translates exactly to 1 in 5.74. By stating that 1 in 6 single adults in Kingston will directly experience a severe housing crisis during their lifetime, our campaign naturally understates the risk to ensure absolute statistical safety. It relies entirely on primary, documented data to offer a transparent and rigorous reflection of the reality faced by our community.