What is the formula for retirement age?

The formula used is: Years = ln((Target×r + Savings) / (Current×r + Savings)) / ln(1 + r)

What if I want to retire earlier than this calculator suggests?

Increase your savings rate, reduce your expected expenses in retirement, or consider a part-time income strategy (Barista FIRE). Even a 5% increase in savings rate can reduce your timeline by 2-4 years.

How accurate is the expected return assumption?

Historical S&P 500 returns average ~10% nominal (7% real). Using 7% is conservative for long-term projections. For a more cautious estimate, use 5-6%. Small changes in return assumptions significantly affect your retirement age.

Does this account for inflation?

If you use real returns (after inflation), the calculator works in today's dollars. A 7% nominal return with 3% inflation equals ~4% real return. We recommend using real return estimates so your FIRE number reflects today's purchasing power.

Retirement Age Calculator

Name: Retirement Age Calculator
Author: TorchFI

When can you actually retire? · Updated 2026

Current Age

Current Savings $

Annual Savings $

Annual Expenses $

Expected Return %

Withdrawal Rate %

How Your Retirement Age Is Determined

Your retirement age depends on the gap between your current savings and your FIRE number, bridged by your annual savings and investment returns. The higher your savings rate and expected returns, the earlier you can retire. Small increases in savings rate can shave years off your timeline thanks to the power of compounding.

Author: TorchFI Team

Frequently Asked Questions

How is retirement age calculator calculated?

The formula is: Years = ln((Target×r + Savings) / (Current×r + Savings)) / ln(1 + r). Enter your values above and click Calculate to see your personalized result instantly. This calculator computes your FIRE number from your annual expenses and withdrawal rate, then determines how many years until you reach it given your current savings, annual savings, and expected…

What inputs do I need for the retirement age calculator?

You need: Current Age, Current Savings, Annual Savings, Annual Expenses, Expected Return, Withdrawal Rate. Default values are pre-filled — adjust them to match your personal finances for a customized result.

Is the retirement age calculator free to use?

Yes — all TorchFI calculators are completely free. No registration, no email required. Calculations run entirely in your browser for maximum privacy. We never see or store your financial data.

How does the retirement age calculator help with FIRE planning?

Calculate your projected retirement age based on your current savings, annual savings, expenses, expected investment returns, and withdrawal rate. See your FIRE number and years remaining to financial independence. This calculator helps you make data-driven decisions about your financial independence journey instead of relying on guesswork.

Last reviewed: June 2026 · Data sources: Methodology & Formulas · Academic References · Correction Log · Editorial Policy