The Easiest Way to Rebalance Your Portfolio Today

Reading time: 7 minutes

Published: January 19, 2025
Modified: January 28, 2025

Rebalancing your portfolio has never been easier! After searching extensively for a tool that could rebalance a portfolio with precision, I realized nothing met my needs—so I created one.

This tool makes it simple to rebalance your portfolio by calculating exact share adjustments based on new investments, updated prices, and target allocations. Whether you’re fine-tuning your holdings or overhauling your strategy, it ensures your portfolio stays on track with your financial goals while saving time and minimizing risk.

To learn how to use this tool, see How to Use the Rebalancing Calculator.


Rebalancing Calculator

Asset Allocation Details

Symbol Current Shares Price ($) Allocation (%)

Make sure to click or tap the Balance button after making any changes to the fields to update your results.


How to Use the Rebalancing Calculator

This guide walks you through how to use the rebalancing calculator to allocate investments across multiple assets, rebalance based on new contributions, and save or reset your data.

Overview of Tables and Fields

  • Asset Allocation Details Table: This is where you input your asset symbols, current shares, prices, and target allocations (in percentages). It represents your portfolio.
  • New Deposit: Enter the amount of money you’re adding to your portfolio for initial balancing or rebalancing.
  • Rebalance Summary Table: Displays the number of shares to buy or sell for each asset to achieve your target allocation.
  • Final Shares Table: Displays the updated number of shares for each asset after rebalancing, along with their final value and allocation percentage.

Now, let’s explore how to use the calculator step by step.

Scenario 1: Balancing Two Assets With an Initial Deposit of $10,000

In this example, let’s model a classic 60/40 allocation between a total stock market index fund, the Vanguard Total Stock Market Index (VTSAX ↗), and a bond index fund, Vanguard Intermediate-Term Bond Index Fund (VBILX ↗).

SymbolCurrent SharesPrice ($)Allocation (%)
VTSAXLeave as 0$14560%
VBILXLeave as 0$1040%
  1. In the Asset Allocation Details table, input the symbols, their prices, and your desired allocations as seen in the table above. Leave the Current Shares as 0 if you are starting fresh.
  2. Enter $10,000 into the New Deposit field.
  3. Press the Balance button to generate the Rebalance Summary and Final Shares tables:
    • The Rebalance Summary table shows you how many shares of each asset you need to buy to reach the target allocation (buy ~41.38 and 400 shares of VTSAX and VBILX, respectively).
    • The Final Shares table shows you the sum of the shares in the Asset Allocation Details and Rebalance Summary tables, along with the total value and percentage allocation of each asset.
  4. Press the Transfer Final Shares to Asset Allocation Details button:
    • The Current Shares in the Asset Allocation Details table will be updated with the final shares from the Final Shares table.
    • The New Deposit field will reset to zero.
  5. Optionally, press the Balance button, which will update the Rebalance Summary table to reflect that you do not need to buy or sell any shares since the Asset Allocation Details table reflects your target allocation.
Balancing two assets
Figure 1. Scenario 1 — Balancing Two Assets
Transferring final shares to Asset Allocation Details table
Figure 2. Scenario 1 — Transferring Final Shares to Asset Allocation Details Table

Note

The calculator computes stock share recommendations to two decimal places to accommodate brokers that allow fractional share transactions. However, most investors may choose to round to the nearest integer for simplicity.

If you round fractional shares to the nearest integer in the Asset Allocation Details table, pressing the Balance button may generate small fractional share adjustments in the Rebalance Summary table. These can typically be ignored, as your overall asset allocation will remain very close to your target.

Scenario 2: Updating Asset Prices

After balancing your portfolio, you should periodically update the asset prices—perhaps quarterly—without changing anything else to ensure that you’re still meeting your allocation targets:

  1. Update the asset prices in the Asset Allocation Details table. Let’s assume that VTSAX has decreased to $130/share and VBILX has increased to $12/share. Leave the Current Shares as they are.
  2. Press the Balance button to update the Rebalance Summary and Final Shares tables. Notice that you must buy 5.6 shares of VTSAX and sell 60.69 shares of VBILX to return to your 60/40 allocation.
  3. Press the Transfer Final Shares to Asset Allocation Details button to update the Current Shares in the Asset Allocation Details table and reset the New Deposit field to zero.
  4. Optionally, press the Balance button, which will update the Rebalance Summary table to reflect that you do not need to buy or sell any shares since the Asset Allocation Details table reflects your target allocation.
Rebalancing shares
Figure 3. Scenario 2 — Rebalancing Shares

Scenario 3: Adding a New Asset and Making an Additional Investment of $10,000

Now, let’s say you want to diversify your portfolio by adding an asset that represents real estate, like the Vanguard Real Estate Index Admiral fund (VGSLX ↗). You want this fund to represent 10% of your portfolio, so you select an allocation for VTSAX (stocks), VBILX (bonds), and VGSLX (real estate) to be 55/35/10.

In addition, you want to invest another $10,000 into your portfolio.

Given that your first two assets—VTSAX and VBILX— have most likely changed in price, you can easily see how complicated it would be to manually calculate the trades you would need to execute to reach your target allocation. Here’s where the real value of the calculator comes shining through!

  1. Use the Number of Assets dropdown above the Asset Allocation Details table to select “3” to add a new row for VGSLX.
  2. Input the symbol for the new asset (VGSLX), its price (e.g., $128), and update the allocations to 55/35/10 for your three assets. Leave the Current Shares for all three assets as they are (including the default of 0 for your new asset, VGSLX). Ensure the total allocation across all assets equals 100%.
  3. Update the asset prices for VTSAX and VBILX in the Asset Allocation Details table. Let’s assume that VTSAX has decreased to $125/share and VBILX has increased to $13/share.
  4. Enter the new investment amount ($10,000) into the New Deposit field.
  5. Press the Balance button to update the Rebalance Summary and Final Shares tables. Notice that you must buy 48.26 shares of VTSAX, 148.49 shares of VBILX, and 15.92 shares of VGSLX to attain a 55/35/10 allocation.
  6. Press the Transfer Final Shares to Asset Allocation Details button to update the Current Shares in the Asset Allocation Details table and reset the New Deposit field to zero.
  7. Optionally, press the Balance button, which will update the Rebalance Summary table to reflect that you do not need to buy or sell any shares since the Asset Allocation Details table reflects your target allocation.
Rebalancing shares
Figure 4. Scenario 3 — Rebalancing Shares
Transferring final shares to Asset Allocation Details table
Figure 5. Scenario 3 — Transferring Final Shares to Asset Allocation Details Table

Using the Generate Link Button

The Generate Link button creates a URL that saves your current inputs. Use it to revisit or share your setup.

  1. Anytime after you’ve entered data in the Asset Allocation Details table and pressed the Balance button, you can press the Generate Link button to generate a URL, which will appear in the field below the button.
  2. Press the Copy button to save the link to your clipboard.
  3. You can paste this link in your browser to repopulate the Asset Allocation Details table with your asset data.
Generate Link button
Figure 6. Using the Generate Link Button

Using the Reset Button

The Reset button clears all data in the Asset Allocation Details table and resets it to the default state. The table will return to two rows with default symbols (SYM1, SYM2) and zeroed-out fields.

Helpful Tips

Explore these tips to make the most of our asset rebalancing calculator:

  • Quarterly Rebalancing: Consider rebalancing your portfolio quarterly to maintain your desired allocations and adjust for market fluctuations.
  • Fractional Shares: The calculator works with fractional shares, so final allocations may include decimals for precision.
  • Revisit Saved Links: Use the Generate Link button to save and return to your portfolio setup anytime.
  • Adjust Allocations Dynamically: If your strategy changes, simply update the Asset Allocation Details table and recalculate.

Conclusion

By leveraging the features and tips outlined in this guide, you can effectively manage and rebalance your investment portfolio to align with your financial goals. Regularly utilizing this calculator will aid in maintaining your desired asset allocation, ensuring your investments remain on track.

See our Investments category page for more articles on asset allocation and the importance of keeping your portfolio balanced.


Scroll to Top