What interest rate does GetReal use?

GetReal uses a representative variable rate based on the RBA cash rate plus an average lender margin. As of August 2026, this is 6.49% per annum. The stress-test rate used in serviceability calculations is this rate plus the 3% APRA buffer — currently 9.49%. The rate is updated periodically, not in real-time.

What is the APRA serviceability buffer rate?

APRA's Prudential Practice Guide APG 223 (August 2022) requires lenders to add a minimum 3 percentage point buffer to the interest rate when assessing serviceability. If the loan rate is 6.49%, the stress-test rate is 9.49%. This buffer has been set at 3% since October 2021.

Can I override the interest rate in GetReal?

Yes. The buying ceiling calculator allows you to enter a custom interest rate — for example if you have a pre-approval from a lender at a specific rate. When overridden, the stress-test rate is still your entered rate plus 3% as required by APRA.

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GetReal — Methodology

Interest rate assumptions

v1.0 — updated periodically from RBA (last reviewed August 2026)

GetReal uses a single representative variable rate based on the RBA cash rate plus average lender margin. This is not a real-time feed — it is updated periodically. The stress-test rate is this rate plus the 3% APRA buffer.

All three serviceability ceilings are sensitive to the interest rate assumption. GetReal uses a market-average variable rate rather than any lender's advertised rate — the tool is designed to give a realistic estimate across lenders, not to reflect any specific product.

Rate component	Current assumption
Representative variable rate	6.49% p.a.
APRA serviceability buffer	+ 3.00%
Stress-test rate	9.49% p.a.
Loan term assumed	30 years, principal and interest

Rate override

The buying ceiling calculator allows a custom rate override — for example, a pre-approval offer from a specific lender. When overridden, the stress-test rate is still entered_rate + 3%.

How we track the RBA rate

GetReal's GitHub Actions pipeline fetches the RBA cash rate automatically from the RBA's F1 statistical table (series FIRMMCRTD). The representative mortgage rate is derived by adding an average lender margin to the cash rate and manually reviewed before each pipeline run.

Rate last reviewed: August 2026. RBA cash rate: 3.85% (as of August 2026). Representative variable rate: 6.49% (cash rate + ~2.64% average margin).

Effect of rate on borrowing capacity — $3,000/month surplus

Stress rate 8.49% (rate 5.49%):   max loan ≈ $404,000
Stress rate 9.49% (rate 6.49%):   max loan ≈ $370,000
Stress rate 10.49% (rate 7.49%):  max loan ≈ $340,000

A 1% rise in the stress rate ≈ $30–35k reduction in borrowing capacity
per $1,000/month of available surplus.
      

↗ Source: RBA — Cash Rate Target