Fidamen

Early Retirement Calculator

This advanced early-retirement planner estimates when you could retire given your current savings, contributions, assumed returns, inflation, and a chosen withdrawal strategy. It supports multiple methods so you can compare a FIRE-style target, a static safe-withdrawal projection, a simple dynamic indicator, and a target-income calculation.

The tool is intended for planning and scenario comparison. It provides deterministic estimates based on the inputs and does not simulate sequence-of-returns scenarios or tax, health, or policy changes. Use conservative assumptions and consult a licensed financial professional for personalized advice.

Updated Nov 25, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 7ac8f7e4e79f • Reviewed by Fidamen Standards Committee

Estimates projected portfolio at planned retirement and compares it to a target portfolio derived from your projected spending and a chosen safe-withdrawal rate.

Inputs

Results

Updates as you type

Years until planned retirement

20

Projected portfolio at retirement

$872,497.42

Target portfolio needed (safe-withdrawal basis)

$1,485,947.40

OutputValueUnit
Years until planned retirement20years
Projected portfolio at retirement$872,497.42USD
Target portfolio needed (safe-withdrawal basis)$1,485,947.40USD
Primary result20

Visualization

Methodology

The calculator projects nominal portfolio growth to the planned retirement year using geometric compounding and a standard future value of an annuity formula for contributions. Spending estimates are inflated to the retirement start year using your inflation assumption.

Multiple methods are provided: a target-portfolio approach (spending × 1/withdrawal rate), a static withdrawal estimate applying a single withdrawal rate to the projected balance, a heuristic dynamic indicator that divides projected balance by inflated spending to estimate years supported, and a target-income calculation solving required portfolio from desired retirement income.

Accuracy and data handling guidance in this tool follows secure handling and software reliability practices recommended by standards bodies. See citations for links to recognized standards and authoritative sources. This tool is not investment advice.

Worked examples

Example: Age 35, retire at 55, $100k savings, $15k/year contributions, 6% pre-retirement return, 2% inflation, 4% withdrawal rate. The planner projects the portfolio at 55 and shows how it compares to the target portfolio needed to fund inflation-adjusted spending.

Use the dynamic-withdrawal indicator to get a rough sense of how many years the projected portfolio could support your estimated first-year retirement spending. This is a heuristic, not a Monte Carlo simulation.

F.A.Q.

Does this tool run Monte Carlo simulations or model sequence-of-returns risk?

No. This calculator provides deterministic, formula-based projections. It does not perform Monte Carlo simulations or model variable sequences of returns. For sequence-of-returns analysis, use a simulator or consult a professional.

Are taxes, Social Security, or pensions included?

No. This tool does not automatically include taxes, Social Security benefits, defined-benefit pensions, or healthcare costs. You may incorporate those by adjusting your target spending or adding them outside the calculator.

What is a safe withdrawal rate?

A safe withdrawal rate is an assumed sustainable first-year withdrawal percentage (commonly 3%–5%) used to estimate the portfolio needed to fund retirement. It is a simplifying assumption and not a guarantee of outcomes.

How should I choose return and inflation assumptions?

Choose conservative, well-reasoned assumptions based on historical ranges, your asset allocation, and current market conditions. Consider running stress cases (lower returns, higher inflation) for planning.

Sources & citations

Further resources

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 7ac8f7e4e79f

What changed (latest)

v1.0.0 • 2025-11-25 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 25, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-25 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 30d748b91fa9