US Retirement Planner — Free 401k Monte Carlo Calculator

⚙️ Your Details

Personal

Your name (for report)

Current age

Target retirement age

Life expectancy

Target monthly income

Retirement Accounts

Current 401(k) balance

Current IRA / Roth IRA

Monthly 401(k) contribution

Monthly IRA contribution

Annual salary

Employer match (% of salary)

Employer match: If your employer matches 100% up to 3% of salary, enter 3. Monthly employer contribution = salary × match% / 1200.

Social Security

Estimated monthly benefit at full retirement age (67)

Find your estimate at ssa.gov/myaccount. If unsure, use $1,500–$2,500 for median earners.

Social Security claiming age

Spousal note: If married, you may claim 50% of your spouse's benefit if higher than your own.

⚠️ Medicare gap detected: You plan to retire before age 65. Private health insurance typically costs $800–$1,500/month. This is modelled as an additional bridge cost.

Estimated monthly health insurance cost (before 65)

Market Assumptions

Expected annual return 7.0%

Inflation rate 2.5%

Portfolio volatility 14%

🇺🇸 Your US Retirement Analysis

Fill in your details and click "Run 5,000 Scenarios" to see your personalised Monte Carlo retirement projection.

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Probability of never running out of money

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Pot at Retirement (Median)

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Monthly Social Security

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Withdrawal Rate

✦ AI Analysis Personalised Retirement Assessment

Retirement Savings Projection — 5,000 Scenarios

Each band shows the spread of outcomes across simulations.

10th–90th %ile

25th–75th %ile

Median

Retirement

SS begins

Social Security Timing Analysis

How your claiming age affects lifetime income and success rate

Monthly Income at Retirement

Target monthly income—

Social Security income—

Gap drawn from savings—

Required withdrawal rate—

Sensitivity Analysis

Scenario	Change	Success	vs Base

RMD Note: The IRS requires Required Minimum Distributions from tax-deferred accounts (401k, traditional IRA) starting at age 73. RMDs are calculated as account balance ÷ IRS life expectancy factor. This model does not separately model RMDs, but they don't reduce total wealth — they only affect timing of withdrawals.

🔒

Unlock Full Analysis — $2.99

Social Security timing comparison, Medicare bridge breakdown, income breakdown, and sensitivity analysis across 8 scenarios.

Fintiq

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Personalised Monte Carlo Analysis

US Retirement
Planning Report

5,000 simulated retirement scenarios — your personal probability of financial security through retirement, including 401(k), IRA, and Social Security analysis.

Prepared for—

Date generated—

Simulations run5,000

For illustrative purposes only. Not financial advice. Fintiq is not registered with the SEC or FINRA. Consult a qualified financial adviser before making retirement or investment decisions. © 2026 Fintiq · fintiq.uk

Fintiq

US Retirement Planning Report

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Executive Summary

Based on your inputs and 5,000 Monte Carlo simulations

0% — certain ruin

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100% — certain success

AI Analysis — Personalised Retirement Assessment

Inputs & Assumptions Used in This Analysis

Fintiq

US Retirement Planning Report

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Retirement Savings Projection

Fan chart showing p10–p90 range of 5,000 simulated outcomes

Median (p50)

p25–p75

p10–p90

Retirement

SS begins

Fintiq

US Retirement Planning Report

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Social Security Timing Analysis

Impact of claiming age on your monthly benefit and success rate

Monthly Income Breakdown at Retirement

Target monthly income	—
Social Security income	—
Gap drawn from savings	—
Required withdrawal rate	—

Fintiq

US Retirement Planning Report

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Sensitivity Analysis

How small changes affect your probability of a secure retirement

Scenario	Change	Success Rate	vs Base

Each scenario re-runs 1,000 simulations with one variable changed. All other inputs held constant at the values you entered.

Fintiq

US Retirement Planning Report

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Methodology

This report uses Monte Carlo simulation to model 5,000 independent retirement scenarios. Each simulation draws annual investment returns from a log-normal distribution. The model runs two phases: (1) Accumulation — contributions and investment growth build the pot; (2) Decumulation — withdrawals reduce the pot, partially offset by Social Security income. A Medicare bridge cost is deducted from the pot for years when retiring before age 65. Social Security benefit is adjusted for claiming age: 70% at 62, 100% at 67, 124% at 70. A simulation "fails" if the pot reaches zero before life expectancy.

Important Limitations

This model does not account for: income tax on 401k/IRA withdrawals, Required Minimum Distributions (RMDs) from age 73, state income taxes, means-tested benefits, long-term care costs, defined benefit pension income, or future changes to Social Security. Spousal benefits are not modelled.

Disclaimer

This report is generated by Fintiq (fintiq.uk) for illustrative and educational purposes only. It does not constitute financial advice, investment advice, or tax advice. Fintiq is not registered with the SEC or FINRA. Always consult a qualified Certified Financial Planner (CFP) or Registered Investment Adviser (RIA) before making retirement or investment decisions. © 2026 Fintiq. All rights reserved.

Will Your Retirement Savings Actually Last?

🇺🇸 Your US Retirement Analysis

Inputs & Assumptions Used in This Analysis

Free Professional Investing Tools

Important Limitations

Disclaimer