FinToolSuite

Legacy Planning Calculator

Updated April 17, 2026 · Planning · Educational use only ·

Estimate the legacy you can leave based on savings and longevity.

Project the inheritance or legacy you can leave based on current savings, spending rate, return rate, and expected longevity.

What this tool does

Enter current portfolio, annual spending, expected return, current age, and planning age. The tool projects the portfolio balance at the planning age for legacy purposes.


Enter Values

Formula Used
Portfolio at year t
Real return rate
Annual spending

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Disclaimer

Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.

Legacy planning is the question: given current savings, spending, and expected longevity, what can realistically be left for beneficiaries? This is different from retirement planning (sustaining lifestyle) — it asks what remains after a life's financial decisions are executed.

The math uses forward projection: portfolio grows at expected return, spending reduces it. At the planning age (often 85-95), remaining portfolio is the legacy. Factors that increase legacy: lower spending rate, higher return, shorter life expectancy. Factors that decrease: higher spending, lower return, longer life (which is the goal but complicates legacy planning).

For most households, legacy is a by-product rather than a primary goal. Focus on sustaining lifestyle through retirement; legacy emerges from what remains. Planning to maximise legacy typically requires under-consumption during retirement years, which may not match values. The calculator makes visible the trade-off so the decision is conscious.

How to use it

Input current portfolio, annual spending in retirement, expected real return, current age, and planning age (often 85-95). The tool projects portfolio balance at the planning age — this is the potential legacy.

What the result means

Projected balance at planning age is the legacy available, in today's purchasing power if using real return. Negative values mean portfolio depletes before planning age — spending pace doesn't sustain to that age. Adjust spending or return assumptions to model different scenarios.

Planning tool. Legal structuring of inheritance requires qualified legal and tax advice.

Run it with sensible defaults

Using current portfolio of 500,000, annual spending of 25,000, expected real return of 4%, current age of 65, the calculation works out to 291,770.46. Nudge the inputs toward your own situation and the output recalculates instantly. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Current Portfolio, Annual Spending, Expected Real Return, Current Age, and Planning Age — do not pull with equal force. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

How the math works

Iterates annual portfolio growth minus spending from current age to planning age. Uses real return for consistency with present-value spending. Balance at planning age is projected legacy. The working is transparent — you can verify every step yourself in the formula section below. No black box, no opaque "proprietary model".

Using this to think, not predict

Financial plans are wrong by month six — new information arrives and reshapes the picture. The point of running projections isn't to be right in ten years; it's to be less wrong in the decision you're making this week.

What this doesn't capture

Real plans get re-run against new information every year or two. The result here is a reasonable direction, not a destination. Treat it as a starting point for thinking, not a commitment to a specific future.

Example Scenario

Current portfolio of 500,000 £ projects to a balance at 90 years based on the inputs provided.

Inputs

Current Portfolio:500,000 £
Annual Spending:25,000 £
Expected Real Return:4
Current Age:65 years
Planning Age:90 years
Expected Result£291,770.46

This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.

Sources & Methodology

Methodology

Iterates annual portfolio growth minus spending from current age to planning age. Uses real return for consistency with present-value spending. Balance at planning age is projected legacy.

Frequently Asked Questions

What planning age should I use?
85-90 for typical planning, 95-100 for conservative planning. Life expectancy at 65 is roughly 82-85 depending on gender. Planning longer ensures portfolio survives longer life; planning shorter assumes assets support earlier end.
Does this account for inheritance tax?
No — shows gross portfolio. Actual inheritance varies enormously by jurisdiction, family structure, and asset types. Qualified tax and legal advice is essential for specific inheritance planning.
What if I need to care for my spouse/parents?
Care costs can be significant (30,000-80,000/year in). Factor expected care costs into annual spending figure during relevant years. Dedicated care cost calculators explore this in detail.
Should I spend down or leave a legacy?
Personal values question, not a math question. The calculator makes the trade-off visible — lower spending leaves more legacy, higher spending leaves less. Decide based on values, not just numbers.

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