Main Residence CGT Calculator Australia (2026–27)
Calculate Capital Gains Tax (CGT) exemptions for your principal place of residence. Model the 6-year absence rule, first-used to produce income market value resets, and partial CGT liabilities.
1. Property Purchase & Sale Price
Includes stamp duty, conveyancing, real estate agent commission, and legal fees.
2. Ownership Period & 6-Year Absence Rule Days
Up to 6 years (2,190 days) of rental period can be treated as tax-exempt if no other property is treated as main residence.
$0 CGT
100% Main Residence Exemption applied under ATO absence rules.
Net Taxable Capital Gain (Added to Income)
$0
Includes 50% discount: $0
Gross Unadjusted Gain
$505,000
Main Residence Partial CGT Apportionment Breakdown
1. The Australian Main Residence CGT Exemption System (2026–27)
The Main Residence Exemption under Subdivision 118-B of the Income Tax Assessment Act 1997 allows Australian tax residents to sell their primary home 100% tax-free.
Special concession rules—such as the 6-Year Absence Rule (s118-145) and the First Used to Produce Income Rule (s118-192)—allow property owners to maintain tax-free CGT benefits even when renting out their former home.
2. 6-Year Absence Rule Partial CGT Benchmarks ($800,000 Gross Gain)
| Rental Absence Duration | 6-Yr Rule Exemption Status | Taxable Gain Ratio | Gross Taxable Gain | Net Assessable Gain (50%) |
|---|---|---|---|---|
| 4 Years Rented (Under 6-Yr Limit) | 100% Full Exemption | 0% Taxable Gain | $0 Taxable Gain | $0 Net Tax Payable |
| 6 Years Rented (Exact 6-Yr Cap) | 100% Full Exemption | 0% Taxable Gain | $0 Taxable Gain | $0 Net Tax Payable |
| 8 Years Rented (2 Yrs Over Cap) | Partial Exemption (75% Exempt) | 25% Taxable Gain (2/8th) | $200,000 Gross Gain | $100,000 Net Assessable Gain |
| 10 Years Rented (4 Yrs Over Cap) | Partial Exemption (60% Exempt) | 40% Taxable Gain (4/10th) | $320,000 Gross Gain | $160,000 Net Assessable Gain |
3. The Mathematics of Partial Main Residence CGT
Partial Taxable Capital Gain (Gain_taxable) for total capital gain (Gain_total), non-exempt rental days over 6-yr cap (Days_nonexempt), and total ownership days (Days_total) is:
Example Calculation:
An owner lived in a home for 4 years, rented it for 8 years (2,920 days), total 12 years (4,380 days), realizing a $600,000 gain:
- 6-Year Rule Exempt Rental Days: 2,191 days (6 years).
- Non-Exempt Rental Days: 2,920 - 2,191 = 729 days (2 years).
- Gross Taxable Capital Gain: $600,000 × (729 ÷ 4,380) = $100,000.
- Net Assessable CGT (50% Discount) = $100,000 × 50% = $50,000 added to tax return.
4. Step-by-Step Guide to Applying Main Residence Exemptions
Determine Home Establishment & Initial Move-in Date
Verify date of settlement and initial move-in to confirm full primary residence status.
Calculate Period of Temporary Absence & Income Generation
Identify dates moved out and duration property was rented to tenants.
Apply 6-Year Absence Rule Election (Section 118-145)
Elect to treat property as main residence for up to 6 years of rental income (or unlimited if unrented).
Apply Market Value Rule at First-Rented Date (If Applicable)
Obtain certified historical valuation if market value rule applies to reset property cost base.
Calculate Partial CGT Liability & 50% Resident Discount
Apportion non-exempt days over total ownership days; apply 50% CGT discount to determine taxable gain.
5. Main Residence CGT Mistakes & Checklist
Attempting to Claim Two Main Residences Simultaneously
Claiming the main residence exemption on both your original home and a newly purchased residence for overlapping periods over 6 months.
Forgetting the 6-Year Cap Reset Upon Re-Occupation
Not realizing that moving back into the home for a period resets a brand-new 6-year absence cap for future rentals.
Claiming Occupancy Tax Deductions for Home Businesses
Claiming interest deductions for a home office, inadvertently triggering CGT on that portion of the home when sold.
Failing to Value Home When Converting to Investment
Using original purchase price instead of market value on first rental date, overcalculating taxable capital gains.
Main Residence Exemption Checklist
Electoral Roll & Utility Bill Alignment
Maintain electoral roll registration, driver license address, and utility accounts at the main residence.
Valuation Report on First Rent Date
Engage a certified practicing valuer to record market value on the day the property is first rented out.
6-Year Absence Tax Election Log
Document that no other property was claimed as your main residence during the 6-year absence period.
Land Size <2 Hectare Verification
Confirm total residential land area does not exceed 2 hectares (5 acres) to maintain full exemption.
6. Main Residence Ownership & Absence Timeline
Establish Principal Place of Residence
Move in immediately after settlement; connect utilities and update electoral roll address.
Start 6-Year Absence Rule Clock
Obtain professional valuation; start 6-year tax-free absence window for rental income.
6-Year Threshold Expiry / Re-Occupation Window
Re-occupy home to reset 6-year clock, sell property tax-free, or begin partial CGT apportionment.
Final CGT Exemption Calculation
Calculate tax-free percentage; report any partial CGT liability on ATO tax return.
Disclaimer: This Main Residence CGT calculator and guide are provided for general educational and informational planning purposes only. Principal place of residence rules, 6-year absence limits, and market value rules reflect 2026–27 Australian Taxation Office guidelines. This page does not constitute formal tax, legal, or conveyancing advice.
Charlotte Smith
Senior Personal Finance & Taxation Specialist at AussieSpot
Charlotte Smith is the lead personal finance advisor and workplace specialist at AussieSpot. Charlotte has over 12 years of experience helping Australian households build budgets, plan savings goals, and manage living costs.
Frequently Asked Questions (FAQ)
What is the Main Residence Exemption in Australian tax law?
The Main Residence Exemption ensures that any capital gain realized when selling your primary home (Principal Place of Residence) is 100% exempt from Capital Gains Tax (CGT), provided the property was occupied as your home throughout your ownership period and sits on land under 2 hectares.
How does the ATO "6-Year Absence Rule" work?
Under Section 118-145 of the ITAA 1997, if you move out of your main residence and rent it out, you can continue treating it as your main residence for CGT purposes for up to 6 years per absence, provided you do not treat any other property as your main residence during that period.
What is the "First Used to Produce Income" market value rule?
If you live in your home first and later convert it into an investment property (without exercising the 6-year rule), the ATO resets your CGT cost base to the property’s market value on the exact day it was first rented out.
Does running a business or claiming a home office affect the Main Residence Exemption?
If you claim occupancy expenses (such as interest or rent) for a dedicated home office or business space, you forfeit a proportionate part of your main residence CGT exemption based on floor area and time used.
What happens if I subdivide my backyard and sell the vacant land block?
Subdividing your main residence land and selling the vacant lot triggers CGT on the land sale. The main residence exemption only applies if the land is sold together with the dwelling.