EquitySight.app
Free full calculator →
EquitySight.app
Free full calculator →
ABS 2021 Census · Updated 21 May 2026
Lock is a coastal suburb in South Australia, Australia, with a population of approximately 253, making it a boutique locality. Located approximately 302 km from the Adelaide CBD, Lock is a coastal area in South Australia. The median household income is $58,500 per year.
Lower income levels in Lock typically translate to more affordable entry points for investors. The coastal setting provides a lifestyle factor that underpins property values.
Official Australia Post postcode for Lock. A postcode may cover multiple suburbs.
Australia Post Postcode Finder →Usual resident population at the most recent census.
Weekly median rent for occupied homes. Live rental data integration coming soon.
Annual median household income (before tax) across all households.
Straight-line distance from the suburb centroid to the nearest capital city CBD. Actual driving distance will be longer.
Estimated 1 school within or near this suburb.
Find schools near Lock on My School →Estimated 1 park and green spaces near this suburb.
Monthly median mortgage repayment for households currently paying off a mortgage.
Proportion of separate houses versus units, townhouses, and other home types. Useful for investors assessing rental demand mix.
Lock is a smaller community of 253 — about 7% of the South Australia suburb median (3,699) — so investors should factor in the narrower buyer pool and longer average time-on-market. Lock's median household income of $58,500/year is 28% below the South Australia suburb median ($80,964) — this is an affordability play where returns lean on yield and patient capital growth rather than demographic premium. Median weekly rent of $120 equates to $520/month — about 102% of the median mortgage repayment of $512/month — meaning rental income covers most of a typical owner's repayment and this is a genuine cash-flow suburb before tax benefits. Lock is 302 km from Adelaide, so the local market tracks regional employment and lifestyle drivers more than CBD-driven commuter demand.
How Lock stacks up against the median of all South Australia suburbs in our dataset. Positive values mean Lock sits above the state median; negative means below.
| Metric | Lock | SA median | Δ vs state |
|---|---|---|---|
| Population | 253 | 3,699 | -93% |
| Median household income | $58,500/yr | $80,964/yr | -28% |
| Median rent (weekly) | $120 | $320 | -62% |
| Median mortgage (monthly) | $512 | $1,616 | -68% |
| Distance to CBD | 302 km | 13 km | +2223% |
| Separate houses | 68% | 73% | -5pp |
Pre-inspection briefing for Lock — every item is derived from public datasets, with full citations in our data sources page.
Limited buy-and-hold upside: a small population of 253 means liquidity is thin and capital growth tends to lag the wider South Australia market over full cycles.
Strong rental coverage: $120/week (~$520/month) covers 102% of the $512/month median mortgage repayment, so the shortfall sits at just $0/month. Investors targeting positive cash flow should shortlist this suburb.
With 68% houses in a 253-person market, renovation margins depend on individual street and aspect rather than any suburb-wide story — do comparable-sales analysis before committing capital.
Run the numbers on a Lock property
Scenario comparison, cash flow analysis, tax modelling, and PDF export — all in one place.
Create free account →Capital-growth expectations for Lock are modest for 2026 — incomes 28% below the SA median of $80,964 and a population of 253 suggest gains will lag headline metro markets. Rental coverage runs at ~102% of the typical mortgage ($520/month rent vs $512/month repayment), keeping cash flow in positive or near-neutral territory. The EquitySight investment score of 29/100 places Lock in the lower tier of Australian suburbs we profile, and overall investor sentiment is cautious heading into the second half of 2026.
Lived in Lock? Help other investors with an honest 100-word review. Sign-in required; all reviews are manually moderated before they appear.
Lock scores 29/100 on our EquitySight investment framework — a weak rating. That score is driven by a population of 253, median household income of $58,500/year and median weekly rent of $120. Whether it fits your portfolio depends on whether you are targeting cash flow, capital growth, or a value-add renovation — all three are scored with suburb-specific numbers elsewhere on this page.
The main demand drivers in Lock are a median household income of $58,500/year, a dwelling mix that is 68% separate houses, roughly 1 schools and 1 parks within the catchment. Together these shape both owner-occupier and tenant demand and are the factors we weight most heavily in the suburb's investment score.
Lock has a usual resident population of approximately 253, compared with a South Australia suburb median of 3,699 — placing it in the lower half of the state's suburbs by size. Population is the clearest proxy for market depth: more residents mean more transactions and typically a shorter average days-on-market on resale.
Lock sits 302 km straight-line from the Adelaide CBD. This is a regional market where CBD distance is only indicative — local industry diversity and commute alternatives matter more.
The most recent census recorded a median weekly rent of $120 in Lock, equating to approximately $6,240/year in gross rental income (state median $320/week). Market rents have typically drifted above the recorded figure — verify against current listings on realestate.com.au and Domain before making an offer.
The median monthly mortgage repayment in Lock is $512, or approximately $6,144/year (vs $1,616/month state median). Stress-test your own borrowing at rates 1–2 percentage points above today's to make sure you can still service the loan through an RBA tightening cycle.
A median weekly rent of $120 works out to $520/month, covering 102% of the median mortgage repayment of $512/month. That means rent exceeds the median repayment by roughly $8/month, so on these numbers Lock leans cash-flow-positive before accounting for strata, council rates, insurance and maintenance. Actual cash flow depends on your deposit, loan terms, ownership costs and marginal tax rate — run the full numbers in our rental yield calculator.
The main risks are a thin buyer pool (253 residents), interest-rate sensitivity on the $512 median mortgage, below-median household incomes ($58,500 vs $80,964 state median), the broader South Australia market cycle. Each of these is covered in the Risk Factors section above with suburb-specific numbers rather than generic warnings.
Every number on this page comes from the ABS 2021 Census of Population and Housing, Australia Post postcode reference data, and OpenStreetMap amenity tiles. The investment score, strategy verdicts, and comparison table are computed deterministically from those inputs — no opinion, no estimation. See our full methodology and the data sources and licences for the formulas we use.