Base price vs full project cost
A low starting price may not include delivery, installation, site works, reports or connections. ROI should use the likely full cost.
ROI Calculator
Granny Flat ROI Calculator
Estimate rental return, yield and payback direction for a Victoria or Melbourne granny flat using four basic inputs.
Estimated project cost
Expected weekly rent
Occupancy rate
Estimated annual expenses
See annual rent, net return, yield and payback direction before your next step.
Indicative only. This is not a final quote, guaranteed rent or guaranteed ROI.
ROI Calculator Tool
Enter Your Cost, Rent and Expense Inputs
Put your key numbers in one place to estimate annual rent, net return, yield and payback direction.
Use your best current estimate
Cost
Estimated project cost and site allowance
Rent
Expected weekly rent and occupancy
Expenses Annual maintenance, insurance and holding allowance
Estimated Result
Your rental return direction
Estimated annual rent
—
Weekly rent x occupancy
Gross yield direction
—
Annual rent vs estimated cost
Payback direction
—
Estimated cost divided by net return
Show detailed net estimate
Annual expenses
—
Your yearly allowance
Estimated net return
—
Annual rent minus expenses
Estimated net yield
—
Net return vs estimated cost
Indicative only. This is not a final quote, guaranteed rent or guaranteed ROI.
After You Calculate
What Your ROI Result Really Means
Use the result as a quick screen. Then check the cost items, rent assumptions and land conditions behind it.
01
Do not compare base price only
A starting package price can make payback look better. Add delivery, installation, site works, approvals and service connections where they apply.
02
Match rent to the dwelling
A 1, 2 or 3 bedroom granny flat will not rent the same in every suburb. Parking, privacy and layout also matter.
03
Read gross before net
Gross yield is useful for a first screen. Net return changes when you add vacancy, management, insurance and maintenance.
04
Use it as a go / no-go check
If the number looks close, check the land before asking for a final quote or relying on the payback direction.
Result Check
Good number? Check what could change it.
Good for
Quick screening
Next check
Site + rent assumptions
A Free Land Check helps test access, services and site costs before you rely on the payback result.
Before You Rely on ROI
What Can Move Your ROI Up or Down?
The calculator is a starting point. The real number can move when cost inclusions, site access, services and local rent demand are checked.
Do not just guess harder. Check the land first, then decide whether the ROI is worth exploring.
Can the home get into the backyard?
Driveway width, slope, fences, trees and crane access can change delivery and installation costs.
How far are the connections?
Power, water, sewer and stormwater distance can change the allowance you should put into the calculator.
Permits, reports and checks
Building permit, engineering, soil, drainage or other reports can affect cost before the ROI number is useful.
Bedroom count and suburb demand
A 1, 2 or 3 bedroom granny flat will not rent the same in every suburb. Use local demand, not a random rent number.
Privacy, parking and layout
Tenants care about entry, light, parking, outdoor space and privacy. These details can change rent appeal.
Next Step
Want a More Realistic ROI Direction for Your Property?
The calculator gives a first view. Your land, access, services and site works can change the real numbers.
1
Submit your property details
Send your address and project goal.
2
We check basic land factors
We look at access, layout and services.
3
Review what may affect ROI
Site conditions may change cost and return direction.
4
Get a clearer next step
Move forward only if the property looks worth checking further.
Indicative only. This is not a final quote, guaranteed rent, guaranteed ROI or approval outcome.
Free Land Check
Turn your estimate into a clearer next step
Share your property details so M Plus can check the site factors behind the numbers.
Address
Access
Services
Calculator FAQ
ROI Calculator Questions
Quick answers before you rely on the numbers.
Use these answers to check your inputs, then submit your address if you want a more realistic ROI direction.
How do I calculate granny flat ROI?
Compare estimated net annual return with estimated project cost.
What cost should I enter?
Use your expected full project cost, not only a package price.
Should I include vacancy?
Yes. Use an occupancy rate instead of assuming rent every week.
What expenses should I include?
Include maintenance, insurance, management and other holding allowances.
Is the return guaranteed?
No. Rent and return depend on the site, suburb and market conditions.
Why check my land after calculating?
Access, services and site works may change cost and ROI direction.
Get a Better ROI Estimate
Your land can change the numbers. Let us check it first.