Chattel Mortgage Calculator Australia

What the chattel mortgage calculator does

The chattel mortgage calculator estimates what a business vehicle or piece of equipment really costs once finance, GST and tax are all taken into account. Enter the price, your deposit or trade-in, the interest rate, the term and any balloon, and it returns the monthly repayment, the balloon due at the end, the total interest over the term and the total amount repaid.

It then goes a step further than a plain loan calculator. Because a chattel mortgage puts the asset in your name from day one, it also estimates the GST credit you can claim on the purchase and the deduction you can claim in the first year from the interest portion of the repayments plus depreciation on the asset.

How a chattel mortgage works

The word chattel simply means a movable item of property, as opposed to land. A chattel mortgage is finance secured over that item. Three features define it:

• You own the asset from settlement. It sits on your balance sheet and you depreciate it.
• The financier takes a registered security interest over the asset, recorded on the Personal Property Securities Register, and releases it when the contract is paid out.
• Repayments are structured like any amortising loan, with the option of a balloon or residual amount left to the end of the term.

That ownership position is what separates a chattel mortgage from an operating lease or a rental agreement, where the financier keeps title and you are simply paying for use. Ownership drives the GST treatment and the depreciation claim, which is why the same asset can produce very different after-tax numbers depending on the contract you sign.

GST and the BAS credit

If you are registered for GST and the asset is acquired for a creditable purpose, the GST included in the purchase price is generally claimable as a credit in the activity statement for the period you acquire it. On a cash basis this normally applies in full in the period of acquisition when the purchase is funded by a chattel mortgage, because you have paid for the asset with borrowed money rather than paying the supplier by instalments.

The calculator separates the tax fraction out of the GST-inclusive price you enter and shows the credit, scaled to your business-use percentage. If you tick off GST registration, the credit is zero and the full price becomes the depreciable cost instead. Note that the repayments themselves do not attract GST on a chattel mortgage: the interest component is input taxed, so there is nothing further to claim month by month.

The balloon or residual

A balloon is a slice of principal you agree not to amortise. It sits at the end of the term as a single lump sum. The trade-off is simple and worth seeing in numbers rather than describing in words:

• A larger balloon lowers the monthly repayment, which helps cash flow.
• Interest keeps accruing on the deferred principal for the whole term, so total interest rises.
• At the end you must pay the balloon in cash, refinance it, or sell the asset and cover any shortfall.

Set the balloon to zero and the loan fully amortises. Move it to thirty or forty per cent and watch both the monthly figure and the total interest change together. The donut chart splits the total repaid into the principal cleared through instalments, the balloon and the interest, so the cost of deferral is visible.

The first-year tax deduction

Two separate deductions come out of a chattel mortgage, and they are often confused with each other:

• Interest. Only the interest portion of each repayment is deductible. The principal portion is a repayment of borrowed money, not an expense. Because the interest share is highest early in the term, the calculator amortises the first twelve months explicitly rather than dividing the total interest by the number of years.
• Depreciation. The asset is written off over its effective life, or immediately if it qualifies for the instant asset write-off. The calculator uses a diminishing value rate you enter, since effective life varies enormously between a laptop, a trailer and a prime mover.

Tick the instant asset write-off box and the calculator tests the cost against the current threshold and your aggregated turnover against the turnover cap. If both tests pass, the whole business-use portion of the cost is deducted in the first year instead of being depreciated. If either fails, it falls back to the diminishing value rate.

Both deductions are apportioned by the business-use percentage. A vehicle used seventy per cent for work gives seventy per cent of the interest and seventy per cent of the depreciation, and the private share is simply not deductible.

Which tax rate applies

The tax saving depends on the entity buying the asset. A company that is a base rate entity is taxed at one rate, a company that is not is taxed at the standard company rate, and a sole trader or partner is taxed at their own marginal rate plus the Medicare levy. Choose the basis in the advanced options; for anything other than a company you can enter the marginal rate that applies to you, because that figure depends on your total income rather than on the asset.

The net first-year cost brings all of it together: your deposit, plus the first twelve repayments, less the GST credit, less the tax saving from the deduction. That number is usually a long way below the sticker price, and it is the figure worth comparing between quotes.

What to check before you sign

• The comparison rate as well as the headline rate, since establishment and monthly account fees can add a great deal over five years.
• Whether the balloon is quoted as a percentage of the price or of the amount financed, because lenders differ.
• Early payout costs, which can be significant on fixed-rate asset finance.
• Whether the vehicle is above the car limit for depreciation purposes, which caps the amount you can write off on a passenger car.

Estimate only

This chattel mortgage calculator produces an estimate, not a quote or tax advice. Fees, credit assessment, the asset's age and condition, the car depreciation limit and your own tax position will all change the outcome. Confirm the numbers with your financier and your registered tax agent before you commit.

About This Chattel Mortgage Calculator

Use this chattel mortgage calculator to get an instant, accurate estimate. The figures follow official ATO guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.