Portfolio Rebalancing Calculator Australia

Plan portfolio rebalancing: measure drift from your target allocation, get the exact trades, and see the brokerage and Australian CGT the rebalance costs.

Australian shares — current value A$

Australian shares — target weight %

International shares — current value A$

International shares — target weight %

Bonds and fixed interest — current value A$

Bonds and fixed interest — target weight %

Listed property — current value A$

Listed property — target weight %

Cash — current value A$

Cash — target weight %

Advanced options

New money to invest A$

Tolerance band %

Brokerage per trade A$

Unrealised gain in the assets you would sell %

Assets held more than 12 months

Your taxable income before the gain A$

When the sale happens

New residential dwelling or affordable housing

Total cost to rebalance —

Portfolio value after new money —

Largest drift from target —

Band breached (1 = yes) —

Total to buy —

Total to sell —

Number of trades —

Brokerage cost —

Capital gain realised on sales —

Taxable gain after the CGT discount —

Estimated capital gains tax —

Marginal rate applied to the gain —

Rebalancing cost as a share of the portfolio —

Share of buying funded by new money —

Australian shares — buy (+) or sell (−) —

International shares — buy (+) or sell (−) —

Bonds — buy (+) or sell (−) —

Listed property — buy (+) or sell (−) —

Cash — add (+) or draw (−) —

Australian shares — drift —

International shares — drift —

Bonds — drift —

Listed property — drift —

Cash — drift —

We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.

What it does

The Portfolio Rebalancing Calculator measures how far each asset class in your portfolio has drifted from its target weight, works out the exact buy and sell amounts that restore the targets, and prices the cost of doing it in brokerage and capital gains tax.

Data sources & parameters

The figures below drive this calculator. We keep them aligned with the latest official guidance, and each result recalculates automatically whenever a value changes.

Parameter	Value	Source	Last updated
CGT discount for assets held over 12 months	0.5	ato.gov.au	Effective 2024-07-01Confirmed for FY2026-27. Ends 2027-06-30 on purpose: Treasury Laws Amendment (Tax Reform No. 1) Act 2026 replaces the 50% discount with cost-base indexation + a 30% minimum tax for gains accruing after 1 Jul 2027. audit 2026-09-23
Resident income tax brackets	Rate schedule	ato.gov.au	Effective 2026-07-01FY2026-27 rates (15% on $18,201-$45,000). Ends 2027-06-30: the scheduled 2027-07-01 row (14%) takes over. audit 2026-09-23
Medicare levy rate	0.02	ato.gov.au	Effective 2024-07-01Confirmed unchanged and current for FY2026-27 against the official source. Open-ended (was to 2027-06-30): statutory, not indexed, no change legislated; audit 2026-09-23
Medicare levy low-income threshold	28,011	ato.gov.au	Effective 2025-07-01Window opened: the threshold is indexed annually and there is no successor row, so closing it at 2027-06-30 would have fallen back to the undated 26,000 row

The formula

Trade for an asset = (Portfolio value + New money) × Target weight − Current value; Cost = Brokerage × Trades + CGT on the discounted gain realised

How it works

It normalises your target weights, applies them to the portfolio including any new money, and takes the difference against each current holding as the trade required. Sales of market assets are converted to a realised gain, halved by the CGT discount where the parcels have been held over twelve months, and taxed at the extra tax the gain adds to your income plus the Medicare levy.

Where it is used

Deciding whether a portfolio has drifted far enough to act
Rebalancing with new contributions instead of selling
Weighing the tax cost of a rebalance against the drift it removes

Worked example

A … portfolio has drifted … from target at its worst point. Restoring the weights means selling … and buying … across … trades, costing … in brokerage and … in capital gains tax — … in total, or … of the portfolio.

What portfolio rebalancing does for you

Portfolio rebalancing is the discipline of returning a portfolio to its chosen asset mix after markets have pulled it out of shape. This calculator shows the drift in each asset class, the exact dollar trades that would restore your targets, and what those trades cost in brokerage and Australian capital gains tax.

The problem it solves is quiet but real. Suppose you set a portfolio at seventy per cent shares and thirty per cent defensive assets. After a strong run in equities, that same portfolio might sit at eighty per cent shares without you doing anything. You now carry more risk than you chose, and you will find out how much more in the next downturn.

Measuring drift properly

Drift is the gap between an asset class's current weight and its target weight, expressed in percentage points.

An asset sitting at forty per cent against a thirty-five per cent target has drifted five points. That is a different and more useful measure than saying it has grown fourteen per cent, because it is comparable across every holding regardless of size. The calculator reports drift for all five asset classes and highlights the largest.

Drift is measured against the portfolio as it stands today, before any new money is added. That keeps the number honest: new contributions change what you need to buy, but they do not change how far the existing portfolio has strayed.

The tolerance band

Rebalancing on every small movement is expensive and pointless. The standard answer is a tolerance band: a drift you are willing to live with before you do anything.

Five percentage points is the most common band and the default here. Some investors use a narrower band on their largest holdings and a wider one on small satellite positions. Others use a relative band, acting when a holding drifts more than a quarter of its own target weight.

Whichever you pick, the value of the band is that it converts an open-ended judgement into a rule. The tool reports whether your band has been breached, so the decision to act is made by the portfolio rather than by how the market felt last week.

Rebalancing with new money first

The single most valuable feature of this calculator is the new money field.

Every sale you make in a taxable account is a capital gains tax event. Every purchase costs brokerage. But directing your next contribution, or an accumulated year of dividends, into the underweight assets achieves part of the same result with no tax at all and no extra trades.

Enter what you are about to invest and the tool shows what share of the required buying it funds. For a portfolio that is still growing, regular contributions alone are often enough to keep drift inside the band indefinitely, and the sell side never has to be triggered.

What a rebalance actually costs

Two costs are priced here.

Brokerage is straightforward: the number of market trades multiplied by your broker's fee. Cash movements are not counted as trades, because moving cash between accounts does not attract brokerage.

Capital gains tax is the larger and more variable cost. The calculator takes the proportion of your sale proceeds that represents unrealised gain, if a quarter of what you sell is profit above cost, enter twenty five per cent, and applies the CGT discount where the parcels have been held for more than twelve months. That discounted gain is then stacked on top of your taxable income and taxed at the resident marginal rates, plus the Medicare levy where you are over the levy threshold.

That stacking matters. A gain that pushes you from one bracket into the next is taxed partly at each rate, which is why the tool computes the difference between your tax with and without the gain rather than applying a single flat rate.

The result is reported both in dollars and as a percentage of the portfolio, which is the figure to compare against the risk reduction you are buying.

Reading the trade list

Each asset class shows a single number: positive to buy, negative to sell. Add them up and the total equals your new contribution, because the portfolio has to end up worth what it started with plus whatever you added.

The trades restore the targets exactly. In practice you will round to whole parcels, and you may choose to leave a small overweight alone rather than pay tax to correct two points of drift. The list is a target, not an order to be executed to the cent.

Practical points for Australian investors

Superannuation is the easiest place to rebalance. Switching between investment options inside a fund is generally not a personal CGT event for you, so most people should rebalance inside super first and use the taxable account only for what is left.

Order of disposal matters outside super. Where you must sell, selling parcels held over twelve months preserves the discount, and selling parcels with the smallest embedded gain reduces the tax bill for the same amount of rebalancing.

Franking credits and distributions do not appear in this tool. If your Australian share holdings pay large franked dividends, receiving them as cash and redirecting them is another way to rebalance without selling.

This calculator is an estimate and is not financial or tax advice. Your actual capital gains tax depends on the cost base of each parcel, your other gains and losses for the year and your full tax position, so confirm anything material with a licensed adviser or your accountant before you trade.

About This Tool: Portfolio Rebalancing

Portfolio rebalancing: use this tool to get an instant, accurate estimate. The figures follow official ATO guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.

Tax year 2026

Frequently asked questions

What is portfolio rebalancing?

Rebalancing is selling some of what has grown and buying what has lagged so the portfolio returns to the asset mix you chose. Markets move at different speeds, so a portfolio left alone slowly becomes riskier or more conservative than intended. Rebalancing pulls it back to the risk level you actually signed up for.

How often should I rebalance?

Two approaches dominate. Calendar rebalancing checks once or twice a year on a fixed date. Threshold rebalancing acts only when an asset drifts more than a set number of percentage points from target, commonly five. Threshold rebalancing usually results in fewer, larger and better-timed trades, and this calculator is built around it.

Can I rebalance without selling anything?

Often yes, and it is the cheapest way to do it. Direct new contributions, dividends and distributions into whichever asset classes are underweight instead of reinvesting them proportionally. There is no brokerage on the sale you did not make and no capital gains tax, because nothing was disposed of. Enter your new money and the tool shows how much of the required buying it covers.

How is the capital gains tax figure worked out?

The tool takes the share of your sale proceeds that is unrealised gain, halves it if the parcels have been held more than twelve months, then works out the extra tax that gain adds on top of your existing taxable income at the resident marginal rates plus the Medicare levy. That extra tax is the estimated CGT.

Does the CGT discount always apply?

Only to assets an individual or trust has held for more than twelve months. Parcels bought within the last year are taxed on the full gain. Because most portfolios hold parcels of different ages, treat the discount switch as an all-or-nothing simplification and check your own holdings before you sell.

Should tax stop me rebalancing?

Not on its own. Tax is a real cost, but so is holding a portfolio that is far riskier than you intended. The calculator puts both on the same page so you can weigh them. A common compromise is to rebalance with new money first, then sell only enough to close the remaining gap.

Does rebalancing guarantee better returns?

No. Rebalancing is a risk management discipline that keeps your portfolio aligned with your intended asset mix, rather than a strategy designed to beat the market. It can occasionally reduce returns in a period when the drifting asset keeps outperforming.

How often do most Australian investors rebalance?

Common approaches are a fixed schedule such as annually, or a tolerance band that triggers a rebalance only once an asset class drifts a set number of percentage points from its target, which the calculator's tolerance band reflects.

About the author

Written and reviewed by

Taha Kheirandish

Economics student and independent researcher

Taha Kheirandish reads tax codes the way other people read maps — to find out where a system actually leads, not where it claims to go.

He is an economics student, and his work here is comparative by design. A pension deferral bonus in Quebec, a commuting allowance in Germany, a rent-increase ceiling in the Netherlands: each is a decision a government made about how money should move, and each reads differently once you set it beside eight others. He builds and checks these calculators across nine markets from primary sources — the regulation rather than a summary of it, the ministry’s own circular rather than a news item quoting it.

That is the editorial standard of the site as well as his habit. Every rate, threshold and bracket here carries the document it was read from and the date it takes effect, and gets re-checked when the law moves rather than when someone happens to notice.

He is a researcher, not a licensed adviser, and nothing on this site is personal financial advice. It is arithmetic done carefully with its sources shown — so that you can check it, and take it to someone who is.

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