Crypto portfolio rebalancing calculator (AUD + CGT)
Configure any number of crypto positions with their current AUD value, target allocation percentage, and cost base. The calculator computes the buy/sell trades needed to hit targets, the gross capital gain on each sell, the ATO CGT payable (50 percent discount applied where the holding period qualifies), and the net AUD proceeds after tax. Designed for AU-resident investors planning a periodic rebalance across multi-asset crypto portfolios.
Calculator
Configure your current portfolio + target allocation. Each row shows the buy/sell action and per-row CGT estimate. Output updates instantly. Default rows are illustrative; replace with your own positions.
| Asset | Current AUD | Target % | Cost base AUD | >12mo | Action | CGT |
|---|
What is rebalancing?
Rebalancing restores a multi-asset portfolio to its target allocation by selling overweight positions and buying underweight positions. Three common triggers:
- Time-based. Quarterly, semi-annually, or annually. Simple but ignores actual drift magnitude.
- Threshold-based. Rebalance only when any position drifts more than a defined band (e.g., 5pp) from target. More tax-efficient because trades only trigger when needed.
- Cash-flow-based. Rebalance only via new contributions (buy underweight positions only). Avoids CGT but requires fresh capital and is slow.
The academic evidence supports rebalancing as a risk-adjusted-return enhancer over multi-year horizons; the mechanic (selling high, buying low) extracts a small premium that compounds across cycles.
CGT treatment in Australia
Every crypto disposal is a CGT event in Australia. A rebalance involving sells of overweight positions triggers a separate CGT calculation per sell:
- Sell proceeds in AUD. Current AUD value of the units being sold.
- Cost base allocated. Proportional fraction of the position's total cost base. Sell 25% of the position → 25% of the cost base allocates to the sold portion.
- Gross capital gain. Sell proceeds minus allocated cost base. Negative = capital loss (offsets other gains in the same FY).
- 50 percent discount. Applied if the position was held more than 12 months from acquisition. Only on positive gains. Section 115-25 of the ITAA 1997.
- Taxable gain. Gross gain minus discount. Added to assessable income and taxed at marginal rate.
- CGT payable. Taxable gain × marginal rate.
The buy side establishes a fresh cost base for the new parcel. No CGT on buys.
Methodology
- Total portfolio. Sum of current values.
- Target check. Targets should sum to 100%. The calculator surfaces a warning if not.
- Per-asset delta. Target value (total × target %) minus current value. Positive = buy; negative = sell.
- Cost base allocation on sell. Sell fraction × asset's total cost base.
- Per-sell CGT. Gross gain × (1 - 0.5 if longTerm else 1) × marginal rate.
- Total CGT. Sum across all sells. Total net proceeds = total sells - total CGT.
Limitations
- Weighted-average cost base only. Real ATO reporting permits FIFO, LIFO, or specific-identification methods per parcel. The calculator uses proportional weighted-average for simplicity. For multi-parcel positions with mixed holding periods, results may differ from a parcel-by-parcel calculation.
- Marginal rate held constant. Large gains can push you into a higher bracket. The calculator uses one rate across all sells.
- No tax-loss netting. If a sell triggers a loss, it would offset gains elsewhere in the same FY. The calculator displays per-sell CGT independently; total CGT can in reality be reduced by netting.
- No fees / slippage. Exchange fees on each trade reduce net proceeds. Subtract approximately 0.5 to 1.0 percent of each trade for typical Australian retail exchange fees.
- SMSF tax differs. SMSF in accumulation uses 15% rate and one-third discount; pension phase is 0%. The calculator's personal-rate model produces the wrong CGT figure for SMSF use - adjust the marginal rate input accordingly (see FAQ).
Related tools
- Crypto CGT Calculator - single-disposal CGT with parcel-by-parcel detail.
- SMSF Crypto CGT Calculator - 15% accumulation, 0% pension, one-third discount.
- Tax-Loss Harvesting Calculator - if any rebalance sells trigger losses, model the EOFY offset.
- Crypto Exit Strategy Ladder - for a single-asset ladder rather than multi-asset rebalance.
- DCA Backtest Calculator - entry-side companion to a rebalanced portfolio.
Frequently asked questions
Rebalancing is the practice of periodically restoring a multi-asset portfolio to its target allocation by selling positions that have grown above target and buying positions that have fallen below. For example, a 60% BTC / 30% ETH / 10% SOL target portfolio drifts over time as the assets perform differently; rebalancing back to the target locks in some gains from the outperformers and adds to the underperformers (a contrarian discipline). Common rebalancing frequencies: quarterly, semi-annually, or threshold-based (rebalance when any position drifts more than 5pp from target).
Yes. The ATO treats every crypto disposal as a CGT event. Selling BTC to buy ETH (whether direct swap or via AUD) is a disposal of BTC AND a fresh acquisition of ETH. Capital gain = AUD sell price minus AUD cost base of the BTC sold. The 50 percent CGT discount under section 115-25 of the ITAA 1997 applies if the BTC sold was held for more than 12 months. The buy side (ETH) is not a CGT event but it does establish a new cost base for that parcel.
Proportional cost-base allocation. If you sell 25 percent of a BTC position worth A$80,000 with total cost base A$30,000, the cost base allocated to the sold portion is A$30,000 × 0.25 = A$7,500. Gross gain = A$20,000 sold - A$7,500 cost base allocated = A$12,500. With 50 percent discount, taxable gain = A$6,250. At a 37 percent marginal rate, CGT payable = A$2,312. This calculator uses the proportional cost-base method for simplicity; real-world ATO reporting permits FIFO, LIFO, or specific-identification per parcel, which can produce different results.
Two considerations. (1) Rebalancing improves risk-adjusted return over multi-year horizons by mechanically selling high and buying low - the academic evidence is consistent across asset classes. (2) Frequent rebalancing erodes the benefit via CGT drag, especially for short-term parcels not yet at the 12-month discount threshold. Compromise: rebalance using threshold rather than time triggers (only rebalance when drift exceeds 5pp) and prefer to sell parcels with the lowest unrealised gain or held more than 12 months. The calculator helps quantify the CGT cost so you can compare against your expected rebalance benefit.
Partially. The mechanics (buy/sell to hit targets) are identical. The CGT calculation differs - SMSFs in accumulation phase use a 33.33% (one-third) discount on 12-month-plus parcels and a 15% effective tax rate, not the 50% discount and personal marginal rate. SMSFs in pension phase pay 0% CGT. For SMSF-specific rebalancing, use the marginal rate field as 10% (15% × 0.667 ≈ 10% effective after discount) for accumulation, or 0% for pension. For a parcel-by-parcel ATO-compliant SMSF report, use the SMSF Crypto CGT Calculator and crypto tax software.
Use the buy-only method: add new AUD into the underweight positions until they reach target weights, without selling overweight positions. This avoids CGT but requires fresh capital. The calculator's buy column shows the AUD needed per asset. Subtract any planned sells if you want a hybrid approach (sell some + add fresh). For a 'no-sell' rebalance, ignore the sell rows entirely and only fund the buys with external AUD.
Only as accurate as your input cost base. The calculator uses the cost base figure you enter; it does not access your actual transaction history. For accurate cost-base figures across multiple buys at different prices, use crypto tax software (Summ, Syla, Koinly) to compute the weighted average cost base per asset. Then plug that figure into this calculator. The CGT estimate is the calculator's output, not a substitute for parcel-by-parcel ATO accounting.
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