PopaDex FIRE calculator settings and results

This guide explains the fields and controls in the PopaDex product. For the formulas, research sources, and limitations behind the projection, read the FIRE calculator methodology.

Open the calculator

Build a projection without creating an account. Sign in only if you want to load existing PopaDex account balances.

Launch the FIRE calculator →

The result is a deterministic estimate based on the inputs you choose. It is not a probability of success, investment recommendation, or promise that a portfolio will last for a particular period.

Start with the right balances

Early-access investments

Enter assets that you could use before pension access age, such as taxable brokerage accounts, ISAs, or other unrestricted investments. Do not automatically enter your full net worth. A home you intend to keep, a car, and household possessions do not directly fund withdrawals.

Pension accounts

Enter balances that are restricted until a stated access age, such as a 401(k), IRA, SIPP, or workplace pension. Check the rules that apply to the account and your country; the calculator does not validate statutory access ages or penalties.

Loading PopaDex accounts

Signed-in users can load balances already recorded in PopaDex. Review the imported figure before using it. An account’s value and its availability for retirement spending are separate questions.

Income, spending, and savings

Annual income

Use an annual figure in the selected currency. The calculator uses income to estimate contributions from the savings-rate field.

Annual expenses

This is current annual spending. When income or expenses change, PopaDex calculates the savings rate as:

(annual income - annual expenses) ÷ annual income

The displayed rate is limited to a range of 0% to 100%.

Desired retirement income

Enter the annual after-tax amount you want the portfolio to support. This may differ from current spending. Include costs that could change after work, such as healthcare, travel, dependants, housing, and tax.

Pension contribution percentage

Use this field to split estimated annual savings between accessible investments and pensions. The current implementation assumes a 20% tax benefit on pension contributions and adds that estimated benefit to accessible contributions. This is a product simplification, not a calculation of your actual tax relief.

Tax fields

The early-access and pension tax fields are estimated effective rates. They are used to gross up the desired retirement income in the model.

The calculator does not model tax brackets, allowances, capital-gains basis, account withdrawal order, contribution limits, or future changes in tax law. Use tax figures that make sense for your scenario and seek qualified advice before making tax decisions.

Investment assumptions

Expected investment return

Enter a nominal annual return. PopaDex subtracts the inflation input to create a simplified real return for the projection.

Inflation rate

The calculator uses:

real return = nominal investment return - inflation rate

This is an arithmetic approximation and assumes a smooth annual return. It is not a simulation of volatile markets.

Withdrawal rate

The traditional strategy calculates the portfolio target as desired retirement income divided by the chosen withdrawal rate, after its tax adjustment. A 4% rate is one scenario, not a guaranteed safe rate.

Choose a strategy

Traditional withdrawal-rate strategy

This option projects accessible and pension balances year by year toward the withdrawal-rate target. Before pension access age, the accessible balance must reach the target. At or after access age, the projected balances can be combined.

Choose this mode when you want a straightforward target derived from an initial withdrawal rate.

Bridge-to-pension drawdown strategy

This option treats accessible investments as a bridge to pension age. It checks whether:

accessible assets can fund the years before pension access; and
pension assets can fund the period from pension age to the life-expectancy input.

Both tests use a smooth real-return assumption and withdrawals at the start of each modeled year. The first whole year in which both conditions pass becomes the estimated FIRE year.

Choose this mode to examine the access gap when much of your wealth is held in restricted retirement accounts. It allows planned depletion and is highly sensitive to the inputs.

Read the results

FIRE number

In the traditional strategy, this is the tax-adjusted retirement-income target divided by the selected withdrawal rate. In the drawdown strategy, it is the projected accessible balance when both bridge and pension tests first pass.

These two results answer different questions and should not be compared as if they use the same definition.

Years to FIRE and FIRE age

The projection advances in whole-year steps. Years to FIRE is the first modeled year in which the strategy’s conditions pass. FIRE age is current age plus that estimate.

A result of 100+ means the calculator did not meet its test within the 100-year projection limit. Review the inputs rather than treating it as a literal age forecast.

Monthly savings target

This is estimated annual savings divided by 12. It reflects the savings rate and income inputs; it is not an optimized contribution recommendation.

Progress

The progress bar compares current accessible savings with the displayed FIRE number. In scenarios involving pensions, taxes, or the drawdown strategy, it is a simple directional indicator rather than a complete readiness measure.

Projection chart

The chart applies the same smooth real return used by the calculator. It does not show market volatility, confidence intervals, or the chance of running out of money.

Test more than one scenario

Keep a base case, then change one assumption at a time:

reduce the expected return;
raise inflation or annual spending;
lower the withdrawal rate;
change pension access age;
adjust tax and contribution estimates.

This shows which inputs have the greatest effect on the date. If a plan works only under the most favorable assumptions, treat the estimate as fragile.

Known omissions

The calculator does not separately model investment fees, random return sequences, country-specific tax law, state pensions, Social Security, annuities, rental income, healthcare shocks, exchange-rate changes, rebalancing, or different asset-class returns.

Review the complete methodology and limitations before relying on the result. To keep the estimate alongside actual balances and net worth history, see the FIRE tracker app.