What does a portfolio weight deviation calculator show?
It compares the current share of each entered holding with a target percentage you supply. For each row it reports the current weight, the difference in percentage points, and the dollar amount by which the current value is above or below the target value calculated from the portfolio total. The calculator does not propose target weights or recommend a trade.
How is the portfolio weight difference calculated?
First, total portfolio value is the sum of the current values entered. Current weight for a holding is its current value divided by that total, multiplied by 100. Weight deviation is current weight minus target weight, in percentage points. A positive deviation means the current weight is greater than the entered target; a negative deviation means it is lower. The target dollar value is total portfolio value multiplied by the target percentage. Dollar difference is target dollar value minus current value. A positive dollar difference means the target value is above the current value; it is a comparison, not an instruction to add money.
For the sample entries, current values total 10,000 currency units: 8,000 in Stocks, 1,000 in Bonds, and 1,000 in Cash. Against targets of 60%, 25%, and 15%, respectively, the current weight deviations are +20, −15, and −5 percentage points. The corresponding target-minus-current dollar differences are −2,000, +1,500, and +500. These values demonstrate the arithmetic only.
Why can a portfolio move away from target weights?
Investor.gov explains that investments may grow at different rates, moving holdings away from an investor’s goals and changing a portfolio’s risk level. It describes rebalancing as a way to bring a portfolio back toward its original allocation. The target allocation itself is personal and depends on factors such as time horizon and risk tolerance; this tool does not evaluate those factors or establish a suitable target. Source: U.S. Securities and Exchange Commission, Investor.gov, Asset Allocation and Diversification (accessed 2026-11-03).
What are the calculator’s limits?
Enter values in a common currency and include every category you want represented. Target percentages must total 100%; current weights are calculated from the values entered and do not need to sum to a preset amount. The tool does not account for taxes, transaction fees, liquidity, account location, pending trades, market movement, or differences in risk among holdings. It assumes each target applies to the total entered portfolio. If a position is omitted or values use inconsistent currencies, results will not describe the intended portfolio.
Frequently asked questions
Does a positive weight deviation mean I should sell?
No. It only means the current percentage is above the target percentage you entered. The calculator gives no trade instruction and does not consider your circumstances, costs, or taxes.
Why must target weights total 100%?
The targets describe the full portfolio represented by the rows. Requiring a 100% total makes the target dollar amounts comparable with the total current value entered.
What does the dollar difference sign mean?
The dollar difference is target value minus current value. A positive result is a target value above the current value; a negative result is below it. Neither sign is a recommendation.
Does this determine an appropriate asset allocation?
No. Investor.gov says allocation is personal and may depend on time horizon and risk tolerance. This tool only compares values with targets you provide.