Portfolio Rebalance Calculator (Two Assets)
Calculate how much of each asset to buy or sell to rebalance a two-asset crypto portfolio to target weights.
How to use this tool
- Enter the current market value of each of your two assets.
- Enter your target percentage weight for Asset A (Asset B gets the remainder).
- Read the dollar trade amounts — a positive number means buy, a negative means sell.
Rebalancing restores your portfolio to its target allocation after one asset outperforms. This calculator tells you exactly how many dollars of each asset to buy or sell. Not financial advice.
Formula
Total = Value A + Value B
Target A ($) = Total × Target A % ÷ 100
Target B ($) = Total × (1 − Target A % ÷ 100)
Trade A = Target A − Current A (positive = buy, negative = sell)
Trade B = Target B − Current B
How it works
The calculator determines the target dollar value for each of two assets given a desired weight for Asset A (with Asset B absorbing the remainder), then subtracts the current holding value from each target to produce the required trade amount. A positive trade amount means you must buy that asset; a negative amount means you must sell. The tool assumes no transaction costs and that the portfolio is rebalanced in a single step at current values.
Worked example
Worked example
- Asset A = $6,000; Asset B = $4,000; target weight for A = 50%.
- Total portfolio = $6,000 + $4,000 = $10,000.
- Target A = $10,000 × 50% = $5,000; Target B = $10,000 × 50% = $5,000.
- Trade A = $5,000 − $6,000 = −$1,000 (sell $1,000 of A).
- Trade B = $5,000 − $4,000 = +$1,000 (buy $1,000 of B).
Sell $1,000 of Asset A and buy $1,000 of Asset B to reach a 50/50 split
Key terms
- Rebalancing
- The process of realigning portfolio weights back to target allocations by buying or selling assets.
- Target weight
- The desired percentage of a portfolio assigned to a specific asset.
- Drift
- The change in actual portfolio weights away from target weights caused by price movements.
- Two-asset portfolio
- A simplified portfolio holding exactly two assets whose weights must sum to 100%.
- Threshold rebalancing
- A strategy that triggers rebalancing only when an asset's weight drifts beyond a set tolerance band, reducing trading frequency.
Frequently asked questions
- How often should I rebalance?
- Common approaches are calendar rebalancing (monthly/quarterly) or threshold rebalancing (when any asset drifts more than 5–10% from target). Fees and taxes affect the optimal frequency.
- Why does selling the winner reduce long-term returns?
- Rebalancing is a risk-control strategy, not a return-maximisation strategy. By trimming winners, you reduce volatility and risk, but you also limit upside if the winner keeps running. It is a tradeoff.