About this calculator
This calculator is for education only and does not constitute investment advice. It takes the portfolio you describe — four holdings, their current values, and the weights you want — and works out the trades that restore those weights. Past returns do not guarantee future results, and rebalancing to a target says nothing about whether the target itself is right for you.
Nothing here is stored and no market prices are fetched: the values you type are the whole picture, so a holding you leave out silently changes every weight. The tolerance band is a nudge, not a rule — a 5-point band means a holding drifting 5 points or less is left alone, which keeps small market moves from generating trades, taxes and fees for no real change in risk.
How to use it
- Enter the current value of each holding and the weight you want it to have. The four target weights must add up to 100%.
- Set the rebalance band in percentage points — the drift allowed before a holding is flagged.
- Read the table: a positive trade means buy that amount, a negative trade means sell that amount. Total buys always equal total sells.
- Only holdings flagged “Rebalance” sit outside your band; the rest can wait until the next check.
The formula
Every trade is computed against the same total, so the buys and sells net to zero by construction: rebalancing moves money between holdings and never adds or removes cash. Drift is measured in percentage points, not percent — a holding moving from 60% to 70% has drifted 10 points, not 16.7%. A holding with a 0% target and a positive value is sold entirely; a holding with a positive target and a zero value is bought from scratch.
Worked example
Stocks $70,000, bonds $20,000, real estate $5,000 and cash $5,000 — a $100,000 total — against targets of 60%, 30%, 5% and 5%, with a 5-point band: current weights are 70%, 20%, 5% and 5%, so target values are $60,000, $30,000, $5,000 and $5,000. The trades are sell $10,000 of stocks and buy $10,000 of bonds; real estate and cash need no trade. Drifts are +10 points for stocks and −10 points for bonds, both outside the band, so both are flagged “Rebalance”. Total buys equal total sells at $10,000.
Sources: Standard weight arithmetic: current weight = holding value / total value; target value = total value × target weight. No prices are fetched and no holdings are stored; all values are entered by you. Last updated: October 2026.
Frequently asked questions
Why do total buys always equal total sells?
Because the target values are slices of the same total: they add up to the current total by construction. If your buys exceed your sells, either a target weight is wrong or the weights do not sum to 100% — and this calculator refuses weights that do not sum to 100%.
Should I rebalance on a schedule or when a band is breached?
Both are used in practice. A calendar check (for example quarterly) catches slow drift; a band check catches fast moves between checks. This calculator supports the band view: set the band, and only flagged holdings need action. Either way, check taxes and trading costs before trading — a small drift is rarely worth a taxable sale.
What if I hold more than four assets?
Group them into the four buckets here — for example, all equity funds under Stocks and all bond funds under Bonds — and rebalance within each bucket separately. The arithmetic is identical at any grouping level, as long as every holding is counted exactly once.
Does rebalancing improve returns?
Not necessarily. Rebalancing controls risk by holding the allocation you chose; it sells what has risen and buys what has fallen, which sometimes helps and sometimes trims winners. Treat it as risk management, not a return strategy — past returns do not guarantee future results.
What formula does this portfolio rebalancing calculator use?
Total = Σ current values; current weight = holding value / total; target value = total × target weight; trade = target value − current value; drift = current weight − target weight Every trade is computed against the same total, so the buys and sells net to zero by construction: rebalancing moves money between holdings and never adds or removes cash. Drift is measured in percentage points, not percent — a holding moving from 60% to 70% has drifted 10 points, not 16.7%. A holding with a 0% target and a positive value is sold entirely; a holding with a positive target and a zero value is bought from scratch. The worked example on this page applies the formula step by step with real numbers, so you can verify the result by hand.