Windfall Gains Tax Calculator VIC

What this calculator works out

This calculator estimates the Victorian Windfall Gains Tax (WGT) the State Revenue Office (SRO) will assess on a rezoning that takes effect on or after 1 July 2023. WGT is charged on the value uplift — the difference between the post-rezoning capital improved value (CIV) and the pre-rezoning CIV — under the Windfall Gains Tax Act 2021 (VIC). It is a commercial tax with material exposure for land developers, joint ventures, family trusts and commercial conveyancers, so the calculation needs to be right before any planning permit application or development costing locks in.

What it does not do: it is not the one-off Victorian transfer duty paid at settlement (use the VIC Stamp Duty Calculator), it is not the annual Victorian land tax (use the VIC Land Tax Calculator), and it is not the Vacant Residential Land Tax (use the VIC Vacant Residential Land Tax Calculator). WGT is a separate, one-off tax triggered by the rezoning event itself and is in addition to all of the above.

The formula and where the rates come from

The thresholds and rates used here come directly from the Windfall Gains Tax Act 2021 (VIC), the SRO's Windfall Gains Tax and WGT Frequently Asked Questions pages, and the SRO's own WGT calculator.

Taxable uplift (post-rezoning CIV − pre-rezoning CIV)	WGT charge
Up to $100,000	nil
Above $100,000 and below $500,000	62.5% × (uplift − $100,000) (marginal)
$500,000 or more	50% × full uplift (flat — the $100,000 threshold no longer applies)

A few mechanics to be careful with:

• Capital improved value (CIV) is the council valuation of land plus improvements, valued immediately before and immediately after the rezoning takes effect. The SRO uses a registered valuer's figure for the binding assessment; the CIV that drives ordinary council rates is generally a useful sanity check but is not the assessment value.
• The switch from marginal to flat at $500,000 is by design. Below $500,000, uplift below the $100,000 threshold is tax-free. At and above $500,000, the entire uplift is taxed at 50%. The two methods meet at almost the same dollar — about $249,999 of WGT on a $499,999 uplift versus $250,000 on a $500,000 uplift — so the cliff is small but the rate band on the assessment notice changes.
• WGT is assessed on the property at large, not per owner. Co-owners share a single assessment.
• WGT applies to rezonings that take effect on or after 1 July 2023. Rezonings gazetted earlier are out of scope, even if the development is still in progress.
• Transitional contracts — sale contracts entered into before 15 May 2021 (and certain pre-existing options and planning permit applications) — are excluded from WGT under the Act, even if the rezoning happens after 1 July 2023.

How to read the inputs

• Pre-rezoning CIV — Capital improved value immediately before the rezoning. For a sanity check, council rates notices show a CIV figure annually; the binding figure for WGT is a registered valuer's number commissioned by the SRO.
• Post-rezoning CIV — Capital improved value immediately after the rezoning takes effect. On a residential-to-commercial or rural-to-residential rezoning the post-rezoning CIV is typically several multiples of the pre-rezoning figure.
• Rezoning date — Use the date the rezoning takes effect (gazette date). Anything before 1 July 2023 returns nil WGT.
• Transitional contract — Tick if the sale contract was signed before 15 May 2021. The exclusion is narrow but absolute when it applies.
• Exemption claimed — Choose the exemption that fits, or No exemption to assess WGT. The 2 hectare residential exemption requires a residential land area input.
• Residential land area (hectares) — Only used when the 2 hectare residential exemption is selected. Sites larger than 2 hectares fall back to a normal assessment.

Worked examples

1. Marginal-band rezoning of a regional residential site. A small landholder owns a 4,500 m² block in regional Victoria with a pre-rezoning CIV of $300,000. A council planning scheme amendment rezones the block from rural to residential and the post-rezoning CIV is $500,000. Uplift = $200,000. The taxable amount is in the marginal band ($100,000 < uplift < $500,000), so WGT = 62.5% × ($200,000 − $100,000) = $62,500. The owner's typical WGT estimate sits around that figure pending the SRO's registered-valuer assessment.

2. Flat-band rezoning at the switch-over point. A developer owns a site with a pre-rezoning CIV of $100,000 that is rezoned to allow medium-density residential, lifting the post-rezoning CIV to $600,000. Uplift = $500,000 — exactly at the flat-band switch. WGT = 50% × $500,000 = $250,000 on the full uplift. Compare this with the marginal-band ceiling of $499,999 uplift, which produces 62.5% × $399,999 ≈ $249,999 — almost identical, but the rate band on the SRO assessment notice is different, which matters for any subsequent objection.

3. Large flat-band uplift on a commercial conversion. A land developer owns a 1.8-hectare industrial site with a pre-rezoning CIV of $500,000. A planning scheme amendment rezones it to mixed-use commercial / residential with a post-rezoning CIV of $1,500,000. Uplift = $1,000,000, well into the flat band. WGT = 50% × $1,000,000 = $500,000. The developer can elect to defer up to 100% of the WGT liability until the next dutiable transaction (sale, transfer or change of beneficial ownership) or for 30 years, whichever happens first. Interest accrues on the deferred amount at the 10-year Treasury bond rate plus a margin set by the SRO.

4. 2 hectare residential exemption — small-acreage rezoning. A family owns a 1.5-hectare lifestyle block with an existing dwelling on the urban fringe. Pre-rezoning CIV is $500,000; the council amends the planning scheme to permit a small subdivision and the post-rezoning CIV jumps to $2,000,000. Uplift = $1,500,000. Without an exemption, WGT would be 50% × $1,500,000 = $750,000. Because the site is residential land of 2 hectares or less with an existing dwelling, the 2 hectare residential exemption applies and WGT = $0. If the same site were 5 hectares the exemption would not apply to the whole site and a normal assessment would proceed.

5. Transitional contract — pre-15 May 2021 sale. A landowner signed a contract of sale on 1 March 2021 that settles in 2026 after a long-running planning amendment finally lifts the post-rezoning CIV from $500,000 to $2,000,000. Without the exclusion, WGT would be 50% × $1,500,000 = $750,000. Because the contract was signed before 15 May 2021, the transitional-contract exclusion in the Windfall Gains Tax Act 2021 (VIC) applies and WGT = $0.

Common pitfalls

• CIV is not site value or contract price. WGT is assessed on capital improved value (land + improvements), not the SRO site value that drives ordinary land tax and not the contract price the developer pays.
• The flat band is not "above $100,000". It is "at or above $500,000 of uplift". Between $100,000 and $499,999 the marginal band still applies and the $100,000 tax-free threshold still bites.
• Multiple owners share one assessment. WGT is calculated on the property, not per owner, so a four-way joint venture does not get four $100,000 thresholds.
• Charitable exemption has a 15-year lock-in. Charitable land used for charitable purposes is exempt, but only if the land remains in charitable use for at least 15 years after the rezoning. A change of use inside the 15 years can trigger a clawback.
• Deferred WGT accrues interest. The deferral option keeps cash in the developer's pocket but adds interest at the 10-year Treasury bond rate plus an SRO margin until the next dutiable transaction (or 30 years).
• Stamp duty and WGT can stack. The buyer of post-rezoning land pays Victorian transfer duty at settlement; the landowner can simultaneously be assessed for WGT on the rezoning that occurred before sale. Model both — see the VIC Stamp Duty Calculator.
• Foreign owners face additional duty too. A foreign land developer of post-rezoning Victorian land can also attract the 8% foreign purchaser additional duty at acquisition. See the VIC Foreign Purchaser Surcharge Calculator.

When to talk to a professional

This calculator is an estimate based on public SRO rate tables and the Windfall Gains Tax Act 2021 (VIC). The typical WGT estimate for the scenarios above is the figure shown, but binding outcomes — especially those involving trusts, joint ventures, partial exemptions, deferral elections, valuation objections or transitional-contract claims — should be confirmed by a Victorian-registered tax lawyer or commercial conveyancer. A registered valuer is needed for the formal pre- and post-rezoning CIV figures the SRO will rely on. Commercial property developments should always confirm WGT exposure with a tax lawyer or commercial conveyancer before commissioning works that depend on the assessment. Nothing on this page is personal financial, tax or legal advice.

Related calculators

• VIC Land Tax Calculator — model the ordinary annual Victorian land tax on site value, including the $50,000 / $25,000 thresholds, 0.375% trust surcharge and 4% absentee surcharge.
• VIC Stamp Duty Calculator — the one-off Victorian transfer duty paid at settlement, including off-the-plan and first home buyer concessions.
• VIC Vacant Residential Land Tax Calculator — the separate annual VRLT on residential land left vacant for more than six months.
• VIC Foreign Purchaser Surcharge Calculator — the 8% additional duty for foreign purchasers of Victorian residential property.
• Negative Gearing Calculator — fold WGT, ordinary land tax and stamp duty into the broader holding-cost picture for an investment property.

Sources:

• State Revenue Office Victoria — Windfall Gains Tax
• State Revenue Office Victoria — WGT Frequently Asked Questions
• State Revenue Office Victoria — WGT exemptions and exclusions
• State Revenue Office Victoria — Windfall Gains Tax Calculator
• Windfall Gains Tax Act 2021 (VIC) — Victorian Legislation
• Victorian Planning Authority