Retirement AtlasA clearer view of retirement.

Calculation methodology

Know what goes
into the numbers.

Model version 1.0. Rule sources checked 2026-09-29; 2026/27 UK tax and Australian contribution settings. Defaults for growth, fees and inflation are editable illustrations. They are not measured personal returns or predictions.

A shared mathematical foundation

Calculations run monthly without intermediate currency rounding. The annual table rounds only for display. A nominal annual investment return r becomes a monthly factor (1 + r)^(1/12). Percentage fees f apply through (1 − f)^(1/12). Contributions and withdrawals occur at month-end.

Today's balance = future balance ÷ (1 + inflation)^years. Scenario lines vary the return by two percentage points while leaving other inputs unchanged. They are deterministic alternatives, not percentiles or confidence intervals.

UK pension drawdown

The model starts at the entered age and ends at the selected horizon. Where selected, upfront tax-free cash is min(25% × pot, entered unused standard allowance), capped at the current standard allowance of £268,275. It is removed from the invested balance and is not added to recurring income.

Monthly balance = max(0, previous balance × investment factor × fee factor − requested withdrawal). An actual withdrawal cannot exceed the available pot. Requested withdrawals either stay fixed in pounds or increase once per year by assumed inflation.

Tax is calculated annually on actual taxable pot withdrawals, entered State Pension and other entered taxable income. The standard personal allowance tapers by £1 per £2 of income above £100,000. Scotland uses its separate non-savings bands. All future tax thresholds and rates are held at their 2026/27 values; each model year is treated as a full tax year, without calendar-year apportionment.

Entered State Pension starts at the user-selected age. State Pension and other income rise with assumed inflation. No entitlement is inferred. The first-year monthly net amount is annual net income divided by twelve; actual PAYE withholding can differ.

Excluded: phased drawdown, UFPLS, protected allowances, tax-code adjustments, savings and dividend taxation, residence exceptions, contributions after drawdown, benefit interactions, annuity pricing, inheritance tax and future rule changes. The model does not determine whether pension access is permitted; the normal minimum access age changes for many people in 2028, and scheme rules can differ.

Australian savings

Regular pre-tax contributions are salary × employer rate plus salary sacrifice. Modelled pre-tax contributions are limited to A$32,500 per year; 15% contributions tax is deducted. Modelled after-tax contributions are limited to A$130,000 and set to zero if the projected opening balance reaches the model's A$2.1 million threshold.

Salary rises by the separate salary-growth input. Voluntary contributions and fixed fees rise with assumed inflation. Current nominal contribution caps and the balance threshold are held fixed throughout the projection. Actual future indexation is not predicted. Opening model-year balance approximates, but does not establish, prior 30 June total super balance.

Returns are entered after investment earnings tax but before the listed fees. Net contributions arrive monthly; annual fixed fees are spread across twelve months. The savings model applies to a regular accumulation account and retirement from age 60 or later.

Australian retirement income

The retirement spending illustration works entirely in today's dollars. It uses the same entered return after earnings tax, adjusted for fees and inflation. This does not model a transition to a tax-exempt pension account. Fixed fees remain constant in real terms.

The annual budget is the highest level income the model can fund each month through the chosen end age, using the projected super balance plus the manually entered Age Pension from its entered start age. The model does not borrow against pension payments that have not started. Unspent pension income is not reinvested. It is a modelled budget, not a recommended or guaranteed withdrawal amount.

Excluded: contribution carry-forward/bring-forward, co-contributions, LISTO, additional Division 293 or large-balance taxes, other assets, household means tests, future Age Pension reassessment, individual access eligibility, transfer balance caps in the retirement phase, mandatory minimum withdrawals and personal tax on retirement income. Warning messages identify cap clipping and some high-income cases; they are not an exhaustive tax assessment.

Maintaining and correcting the model

Published rate changes require a source review, versioned data update and checks of boundary cases. We keep the rule-review date separate from future projection assumptions. Please report a suspected issue using example data and an official source.

Official reference points

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