📊 Optimal Lazy Portfolio Rebalancer

Minimize transaction costs while maintaining your target allocation

Portfolio Input

$
Asset Name Target % Current Value Share Price

Rebalancing Results

👆 Enter your portfolio details and click "Calculate Rebalancing" to see results

How It Works

The "Lazy" Approach

Traditional rebalancing involves selling overweighted assets and buying underweighted ones, which creates transaction costs and potential tax implications. The "lazy" approach minimizes these issues by:

  • When contributing: Only buy underweighted assets
  • When withdrawing: Only sell overweighted assets
  • Never unnecessary transactions: Avoid selling to buy back at different prices

The Algorithm

The calculator uses fractional deviation optimization:

Fractional Deviation = (Actual Allocation / Target Allocation) - 1
  • For contributions: Maximizes the minimum fractional deviation
  • For withdrawals: Minimizes the maximum fractional deviation
  • Proportional allocation: Distributes money to improve all asset allocations simultaneously

Benefits

  • ✅ Reduced transaction costs
  • ✅ Minimized taxable events
  • ✅ Mathematically optimal allocation
  • ✅ Simple to execute

About This Calculator

Privacy & Security

🔒 All calculations are performed entirely in your browser. No financial data is transmitted to any server. Your portfolio information remains completely private.

Accuracy

📊 This calculator uses high-precision JavaScript arithmetic to ensure accurate results for financial calculations. Results are rounded for display but calculations maintain full precision.

Technology

🚀 Built with modern web technologies:

  • Vanilla JavaScript for maximum compatibility
  • CSS Grid and Flexbox for responsive design
  • Web standards for accessibility
  • No external dependencies

Disclaimer

⚠️ This tool is for educational and informational purposes only. It is not investment advice. Please consult with a qualified financial advisor before making investment decisions.