FIRE Calculator

A comprehensive Financial Independence, Retire Early (FIRE) retirement planning calculator. Runs entirely in the browser with no backend — your data stays on your device.

Features

• Multi-person households — model 1-2 adults with separate accounts and ages
• Account types — Traditional 401(k)/IRA, Roth, Taxable Brokerage, HSA, Cash/Bonds, 457(b), Generic
• Tax-aware withdrawal optimization — fills low brackets with traditional, then LTCG, then Roth
• Federal + state taxes — all 50 states + DC with progressive brackets
• Roth conversion strategies — fill 12%/22%/24% brackets during low-income years
• Social Security — early/delayed claiming adjustments, taxable income calculation
• Pension support — defined-benefit income with configurable COLA
• ACA subsidy modeling — 400% FPL cliff-aware withdrawal optimization
• IRMAA Medicare surcharges — 2-year MAGI lookback with Roth conversion look-ahead
• Monte Carlo simulation — per-asset-class returns with correlated equity/bond streams
• Historical backtesting — 154 years of S&P 500 and US government bond data (1871-2024)
• Asset allocation glide path — configurable safe-years buffer at start/end of retirement
• Austerity mode — automatic spending reduction when cash drops below floor
• Variable spending phases — different spending levels by age range
• Healthcare cost modeling — separate pre-65 and post-65 costs with healthcare inflation
• Dividend income tracking — taxable dividend MAGI impact on ACA/IRMAA
• Data import/export — JSON backup and restore

Quick Start

npm install
npm run dev

Open http://localhost:5173 in your browser.

Scripts

Command	Description
npm run dev	Start development server
npm run build	Type-check and build for production
npm test	Run all tests
npm run test:watch	Run tests in watch mode
npm run lint	Run ESLint

Deploying to AWS

The included CloudFormation template and GitHub Actions workflow deploy the app as a static site on S3 behind CloudFront.

Prerequisites

• An AWS account
• A GitHub OIDC provider already configured in your AWS account (docs)
• An ACM certificate in us-east-1 covering your domain
• A Route 53 hosted zone for your domain (optional, for custom domain)

1. Deploy the CloudFormation stack

# Find your existing OIDC provider ARN
aws iam list-open-id-connect-providers

# Deploy the stack
aws cloudformation create-stack \
  --stack-name fire-calculator \
  --template-body file://infra/stack.yml \
  --parameters \
    ParameterKey=BucketName,ParameterValue=your-bucket-name \
    ParameterKey=GitHubRepo,ParameterValue=your-org/fire-calculator \
    ParameterKey=GitHubOIDCProviderArn,ParameterValue=arn:aws:iam::ACCOUNT_ID:oidc-provider/token.actions.githubusercontent.com \
    ParameterKey=DomainName,ParameterValue=fire.example.com \
    ParameterKey=CertificateArn,ParameterValue=arn:aws:acm:us-east-1:ACCOUNT_ID:certificate/CERT_ID \
  --capabilities CAPABILITY_NAMED_IAM

# Wait for completion
aws cloudformation wait stack-create-complete --stack-name fire-calculator

# Get the outputs
aws cloudformation describe-stacks --stack-name fire-calculator \
  --query 'Stacks[0].Outputs' --output table

2. Configure GitHub secrets

Set these repository secrets from the stack outputs:

Secret	Stack Output
AWS_ROLE_ARN	DeployRoleArn
S3_BUCKET	BucketName
CLOUDFRONT_DISTRIBUTION_ID	CloudFrontDistributionId

3. Configure DNS

Create a Route 53 alias record pointing your domain to the CloudFront distribution.

4. Deploy

Push to main and the GitHub Actions workflow will automatically build, test, and deploy.

Infrastructure details

The CloudFormation stack (infra/stack.yml) creates:

• S3 bucket — private, all public access blocked, accessed only via CloudFront OAC
• CloudFront distribution — HTTPS-only, HTTP/2+3, gzip compression, security headers (CSP, HSTS, X-Frame-Options), PriceClass_100 (US/Canada/Europe)
• IAM deploy role — OIDC-federated, scoped to your GitHub repo's main branch, with minimal permissions (S3 put/delete + CloudFront invalidation)
• Security headers policy — Content-Security-Policy, Strict-Transport-Security, X-Content-Type-Options, X-Frame-Options, Referrer-Policy

Tech Stack

• React 18 + TypeScript + Vite
• Tailwind CSS
• Recharts (charting)
• Vitest (testing)

License

This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0).

This means you are free to use, modify, and distribute this software, provided that:

• You include the original copyright and license notice
• You disclose your source code when distributing
• If you run a modified version as a network service, you must make the source available to users
• Derivative works must use the same license