Why aging trajectory belongs in retirement planning

People spend roughly five hours a year planning for their retirement — fewer than they spend researching a major appliance. The disproportion is not laziness or indifference. It is the symptom of a planning frame that has not earned the time, because it gives generic answers to the questions that matter most about how their lives will unfold.

Why averages aren't enough

Retirement planning, as practised by most providers, advisors, and individuals, is built on a small set of inputs: age, sex, current savings, planned contributions, target retirement age, and a payout choice. These are combined with population-level mortality and morbidity tables to produce a projection. The framework is venerable, transparent, and well understood — and it is also coarse.

Two people who happen to share a birth year may have radically different physiological trajectories. One has been physically active for thirty years; the other has not. One sleeps well, the other has been chronically stressed. The first will likely outlive the second by a meaningful margin, and will need a retirement plan that funds a longer life.

A different anchor

The thesis is straightforward: retirement planning should start from how a person is actually aging, not from the year on their identity document. Modern smartphones already capture data that, properly analysed, yields a personalised aging trajectory. Combining that trajectory with the standard financial inputs produces projections grounded in the individual rather than averaged across the population.

What changes in practice

Six retirement decisions get reshaped when aging information is on the table — planning horizon, sustainable withdrawal rate, asset allocation, tax-efficient cadence, healthcare reserve, retirement age. None of these reshapings is a recommendation by the product. Each is a decision the user — together, where applicable, with their advisor — makes. The product's role is to make the input personal rather than averaged.

For more on the specific decisions and how they shift, see the homepage decision matrix or the whitebook for a full treatment.