Capital gains tax discount calculator

What the 2026 tax reform changes for CGT

The Treasury Laws Amendment (Tax Reform No 1) Act 2026 (Act No. 49 of 2026), which passed parliament on 25 June 2026, implements the 12 May 2026 Budget measure. For CGT events on or after 1 July 2027, the 50% CGT discount is replaced by cost-base indexation for assets held more than 12 months, with a 30% minimum tax on the resulting real capital gain. The new regime applies to individuals, trusts and partnerships — including their pre-1985 CGT assets, which were previously outside CGT. Recipients of certain income support payments (including the Age Pension and Jobseeker) are exempt from the 30% minimum tax. Complying super funds and companies keep the existing regime for post-1985 assets: super continues at the 33.33% discount, companies with no discount on the gross gain. Senate amendments made during passage — a charitable-gift reduction to the minimum-tax base and a higher small-business active-asset turnover threshold — left the core mechanics unchanged; some supporting legislative instruments are still to come.

Who the new regime affects

The shift from 50% discount to indexation applies to individuals, trusts (gains assessed to resident beneficiaries) and partnerships (flowed through to partners). Complying super funds — including SMSFs — stay on the 33.33% discount. Companies continue on 25% or 30% of the gross gain with no discount applied. Non-residents remain denied the 50% discount on the post-8 May 2012 portion of TAP gains, with apportionment rules unchanged.

The transitional split at 1 July 2027

Gains on assets already held at the cutoff are split into a pre-1 July 2027 portion (eligible for the 50% discount) and a post-1 July 2027 portion (indexed, with the 30% minimum tax). The Act sets the split by deeming the asset disposed of and reacquired at its market value on 1 July 2027: the pre-portion is the notional gain up to that value (deferred until the actual sale), and the post-portion is measured from the indexed market value. Market value is the default; a taxpayer may instead elect an ATO apportionment method, to be set by the Minister by legislative instrument and not yet released. This calculator models the market-value path — enter your 1 July 2027 valuation when the field appears.

The new residential property carve-out

Under the Act as passed, keeping the discount is the default for these assets: gains on new residential dwellings retain the 50% discount (s 115-102) and gains from affordable housing retain a discount of up to 60% (s 115-125), and both sit outside the 1 July 2027 deemed disposal and the 30% minimum tax. The taxpayer may instead irrevocably elect cost-base indexation. What counts as a "new residential dwelling" is still to be set by the Minister by legislative instrument. The calculator models both asset types — pick them in the Asset type field, and use the election checkbox to compare the retained discount against the indexation path.

What this calculator models

CGT event A1 disposals only, for a single client, across the four entity types practitioners model day-to-day (Individual, Trust, SMSF, Company) — plus, for individuals and trusts, the residential asset types the Act treats differently (new residential dwellings and affordable housing, with their elect-out into indexation). For disposals straddling 1 July 2027 it also takes a market value at that date to split the gain. The Cost base field expects the total across the five ATO elements — first (acquisition cost), second (incidental costs of acquisition and disposal: brokerage, stamp duty, legals), third (non-deductible costs of ownership for assets acquired after 20 August 1991), fourth (capital improvements), fifth (capital costs of preserving or defending title) — plus any AMIT cost-base adjustments for managed funds and ETFs. Use the Inputs drop-down on the result card to echo what was entered and copy figures into firm working papers.

What this calculator doesn't model

The ATO apportionment method (the alternative to a 1 July 2027 market valuation, pending its legislative instrument), the day-based proration of the affordable-housing discount (the calculator assumes affordable use for the full ownership period), a company's pre-1985 catch (caught by the Act but its cost-base mechanics aren't yet specified — the calculator still shows that case as exempt), the income-support / Age Pension exemption from the 30% minimum tax, the small business CGT concessions (15-year exemption, 50% active asset reduction, retirement exemption, rollover), the main residence exemption (full or partial), foreign-resident TAP apportionment, scrip-for-scrip rollover, demerger relief, deceased estate cost-base rules, in-specie transfers, capital losses carried forward, Medicare levy and offsets. SMSF pension-phase 0% applies to segregated current pension assets — unsegregated funds use the ECPI proportion, also not modelled. Run client-specific scenarios through your firm's working papers; this is general information, not financial, tax or legal advice.

CGT discount history

The 50% CGT discount has applied to disposals by individuals and most trusts since 21 September 1999, replacing the indexation method that applied from the introduction of CGT on 20 September 1985. The 2026 Tax Reform No 1 Act revives indexation — in modified form, with the 30% minimum tax rate — from 1 July 2027.