Cernarus

Financial Independence Calculator

This planner helps estimate how much you need to achieve financial independence under multiple commonly used approaches: a safe withdrawal rate (FIRE), coast-FIRE (no further contributions), and an income-replacement projection that accounts for expected Social Security or pensions.

Results are deterministic projections using user-provided inputs and standard future-value formulas. Use the scenarios to compare assumptions (returns, inflation, withdrawal rate) and to understand sensitivity; this tool does not replace personalized financial advice.

Updated Nov 15, 2025

Estimate the target nest egg using a configurable safe withdrawal rate and project current savings plus planned contributions to retirement.

Inputs

Results

Updates as you type

Target nest egg

$1,853,944.10

Projected savings at retirement

$763,238.66

Projected shortfall / surplus

$1,090,705.44

Years until retirement

25

OutputValueUnit
Target nest egg$1,853,944.10USD
Projected savings at retirement$763,238.66USD
Projected shortfall / surplus$1,090,705.44USD
Years until retirement25years
Primary result$1,853,944.10

Visualization

Methodology

We compute future spending by inflating the user-specified current spending by the inflation rate over years until retirement.

Nest-egg targets use the specified withdrawal rate (for example, a four percent rule means target equals future spending divided by 0.04).

Savings projections use standard discrete future-value formulas: grow current savings by (1 + return)^n and add the future value of an annual contribution treated as an end-of-period annuity.

Coast-FIRE principal is the present principal that, under the assumed return, grows to the nest-egg target without additional contributions.

All percentages are entered as whole numbers (for example, 6 means 6%).

Key takeaways

Use multiple scenarios and conservative assumptions to understand potential shortfalls.

This tool follows secure development and transparency practices recommended by standards bodies, but it is not a regulated financial advisory product.

Expert Q&A

How accurate are these estimates?

Estimates are as accurate as the inputs and assumptions. They use deterministic formulas and do not model market sequence risk, taxes, or unforeseen events. Use scenarios to test sensitivity. This tool is educational and not a substitute for licensed financial advice.

Which withdrawal rate should I use?

Common practice uses 3%–5% for long-term sustainability depending on portfolio mix and retirement length. Lower rates reduce the chance of running out of money but increase the required nest egg.

Does this account for taxes and sequence of returns?

No. This planner uses average annual return assumptions and does not simulate sequence-of-returns risk, taxes, or changing spending patterns. For those elements use stochastic Monte Carlo planning or consult a financial planner.

What does 'coast-FIRE' mean here?

Coast-FIRE computes the principal you would need today so that, if you stopped contributing and invested with the assumed return, it would grow to your target nest egg by retirement.

How should I choose expected returns and inflation?

Choose conservative, well-documented long-term estimates. Consider running multiple scenarios (optimistic, baseline, conservative) to see the range of outcomes.

Sources & citations

  • National Institute of Standards and Technology (NIST) – secure development & data handling guidance https://www.nist.gov
  • International Organization for Standardization (ISO) – risk management principles (ISO 31000) https://www.iso.org
  • Institute of Electrical and Electronics Engineers (IEEE) – algorithmic transparency best practices https://www.ieee.org
  • Occupational Safety and Health Administration (OSHA) – general safety standards https://www.osha.gov
  • Social Security Administration – retirement benefits information https://www.ssa.gov