The Finance AlgorithmTFA

Chattel Mortgage Calculator

Calculator

Calculate business vehicle finance with chattel mortgage and tax benefits

Free to useNo data storedAI insightsUpdated: February 2026

Chattel mortgage is a popular business vehicle finance option. You own the car from day one, claim GST credits immediately, and deduct interest and depreciation. This calculator shows the after-tax cost.

Enter Your Details

Enter Your Details

$
$
%
%
%

Percentage used for business purposes

%

Company tax rate or your marginal rate

Real-World Examples

Ute for Tradesman

$55,000 ute (inc GST), 5 years at 7%, 80% business use, 25% company tax rate.

Inputs:

price:55,000rate:7term:5businessUse:80taxRate:25
GST credit: $4,000. Annual depreciation deduction: ~$24,000 (instant write-off). Monthly repayment: $990. After-tax effective cost significantly reduced.

Frequently Asked Questions

Glossary

Chattel Mortgage
A business loan where the vehicle is security (chattel) but you own it from the start.
GST Credit
Businesses can claim back the GST component of the vehicle purchase (business portion).
Instant Asset Write-Off
Immediate tax deduction for eligible business assets (thresholds vary by year).
Logbook Method
Keeping detailed records to prove business vs private use for tax purposes.

Disclaimer: This calculator provides estimates only and should not be relied upon for financial decisions. Interest rates, fees, and policies change frequently. Always verify information with lenders directly. This is general information, not personal financial advice. Consider seeking advice from a licensed mortgage broker or financial advisor.

Last updated: February 2026

How to Use
  1. Enter the vehicle price including GST
  2. Add any deposit and set loan terms
  3. Optionally add a balloon payment
  4. Enter your business use percentage
  5. Set your company or marginal tax rate
Key Information
  • You own the vehicle immediately (on finance)
  • GST credit can be claimed upfront (business portion)
  • Interest and depreciation are tax deductible
  • No FBT if logbook shows 100% business use
Pro Tips
  • Keep a detailed logbook to prove business use percentage
  • Consider instant asset write-off thresholds for tax deductions
  • Balloon payments are common to reduce cash flow impact
  • Compare with novated lease if there's significant private use
Avoid These Mistakes
  • Claiming 100% business when there's private use (ATO audits this)
  • Not claiming GST credit when eligible
  • Forgetting to budget for balloon payment
  • Not considering FBT for private use component
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