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Australia-wide · Buying before selling

Bridging loan calculator

Buying before you sell? See the debt you are left with once the old home settles, and the interest while you carry both.

Arithmetic checked · rates are yours The bridging rate is the one you enter: no official schedule sets it.

Example figure — replace it with your own. Pick your state to fill in the stamp duty from its schedule, or type your own figure.

Example figure — replace it with your quotes.

Your tally

End debt after the sale

$460,000

About $3,216.39 a month once the old home settles (30 years at the same rate).

How it’s worked out

Peak debt (both homes carried)$1,240,000
Interest during the bridge (paid monthly)$46,500
Net proceeds from your sale−$780,000
Peak debt down to end debt

Next: covering only the deposit → Deposit bond calculator

Lender policies differ on maximum peak LVR, assessment rates and fees. Stress-test with a lower sale price and a longer bridge — then compare actual lender quotes.

Found the next home before selling the current one? This bridging loan calculator shows your peak debt, the interest while you carry both, and the end debt you'll live with after settlement — independent numbers, not a lender's sales tool.

The four numbers that decide a bridge

  1. Peak debt — your current mortgage plus the entire new purchase (price + costs). The most you'll ever owe, and what the lender secures against both homes.
  2. Bridge interest — interest-only on the peak debt for every month until settlement. Paid monthly it's a cash-flow cost; capitalised it compounds into the loan.
  3. Net proceeds — what the old home actually clears after agent and legal fees. The single most dangerous assumption: be conservative.
  4. End debt — what's left when the dust settles. This is the mortgage you actually live with, so judge the whole move by it, not by the scary peak.

What a longer sale really costs

Default scenario ($1,240,000 peak at 7.5%), by months on the bridge:

What a longer sale really costs
Bridge lengthInterest, paid monthlyInterest, capitalisedEnd debt if capitalised
3 months$23,250$23,396$483,396
6 months$46,500$47,233$507,233
9 months$69,750$71,519$531,519
12 months$93,000$96,264$556,264

Every extra month costs roughly $7,750 here — the strongest argument for pricing the old home to sell, not to dream.

Worked example

Upgrading from an $800,000 home to a $900,000 one. Carrying the $300,000 mortgage plus the purchase makes peak debt $1,240,000. 6 months at 7.5%, paid monthly, costs $46,500 in bridge interest. The sale clears $780,000 after costs, leaving an end debt of $460,000 — about $3,216.39/month over 30 years.

The buying-costs field is doing heavy lifting. Pick the new home’s state above and the duty is filled in from that state’s schedule; every state’s figure sits side by side on the stamp duty by state page. If your end-debt LVR tops 80%, the LMI calculator tells you what that adds.

Frequently asked questions

How does a bridging loan work?
It lets you buy the new home before the old one sells. The lender temporarily carries both: your existing mortgage plus the full cost of the new purchase (this total is your peak debt). When the old home settles, its net proceeds pay the bridge down, and whatever remains becomes your ongoing mortgage (the end debt).
How is bridging loan interest calculated?
This calculator charges it interest-only on the peak debt, at the bridging rate you enter — the rate itself is the lender's to quote. You either pay it monthly, or it's capitalised — added to the loan and compounding — so a longer sale means a visibly bigger end debt. This calculator shows both modes.
What is peak debt and end debt?
Peak debt = old mortgage + new home price + purchase costs (the most you owe, mid-bridge). End debt = peak debt (plus capitalised interest) minus the net sale proceeds of the old home. How a lender weighs each — against the security of both homes, against your income — is its own credit policy, so ask before you apply.
How long can you have a bridging loan?
The maximum term is set by each lender's policy, so confirm it before you sign; this calculator runs up to 24 months. You pay interest only for the months until the old home settles, which is why the months field moves the answer so much. What happens if the sale runs past the term — a different rate, a requirement to sell — is in the lender's contract, not in any public schedule.
Do you make repayments during the bridge?
That depends on the product, so ask the lender. This calculator models the two ends: interest on the whole peak debt paid as it falls due, or none paid at all, with the interest capitalised and compounding monthly. Some products keep your existing loan repayments going alongside a capitalised bridge; that split is not modelled here. Not paying along the way has a price, which is why the capitalised column below grows faster.
What are the main risks of bridging finance?
Three: the old home sells for less than the valuation (bigger end debt), it takes longer to sell (more months of interest, and whatever the contract says happens at the end of the term), and overcommitting to a new purchase on optimistic sale assumptions. Stress-test this calculator with a lower sale price and a longer bridge before committing.

Keep tallying

Deposit timing

Deposit bond calculator

A smaller version of the same problem: covering the deposit before your sale settles.

Open calculator →

All 8 states

Stamp duty by state

The duty on the new home belongs in your buying costs — every state's, compared.

Open calculator →

Australia

Rent vs buy calculator

Weighing up whether to buy at all? Run the honest comparison.

Open calculator →

Embed this calculator on your site

Conveyancers, brokers, agents: add the Bridging loan calculator to your own website free of charge. Paste this snippet anywhere HTML is accepted — it stays up to date automatically, because it renders from the same tested engine as this page. We only ask that the attribution line stays visible.

The attribution links carry rel="nofollow", which is what Google asks of any link distributed through a widget — so adding this cannot affect your own site's rankings either way. See every calculator you can embed, and the terms, on one page.

Method

Peak debt = current mortgage + new price + buying costs. Choosing a state fills the buying costs with that state’s stamp duty for a home you will live in (the same engine as the state calculators); legals and anything else are yours to add. Interest-only on peak debt at your rate; capitalised mode compounds monthly. End debt = peak (+ capitalised interest) − net sale proceeds. End-debt repayment shown as 30-year principal & interest at the same rate. Arithmetic checked 28 August 2026. General information only — not financial or credit advice.

Assumptions

Bridge interest accrues monthly on the whole peak debt. By default it is paid as it falls due; tick “Capitalise the interest” and it is added to the balance instead, compounding monthly. Which structure a lender offers is its own policy. Sale proceeds net of selling costs repay the bridge at the end of the period; rates are held constant; lender-specific fees and peak-LVR caps vary and aren't modelled. The engine is covered by automated accuracy tests — see the methodology. General information only — not financial advice.