NZ Vehicle Expense Planner
Convert a sample logbook into a business-use percentage and compare the two main IRD vehicle-expense methods.
Include eligible running costs and depreciation calculated under IRD rules.
Higher estimated claim
$11,412.00Kilometre-rate method
Business use
60.00%90-day period met
Kilometre-rate claim
$11,412.002025-26 published rates
Actual-cost comparison
$9,000.00Observed business-use share
- • Observed business use is 60.00% (5,400 of 9,000 km).
- • Once you choose kilometre rate or actual costs for a vehicle, IRD generally requires you to keep using that method while you own it.
- • The logbook covers at least 90 consecutive days. IRD says the result can generally be used for up to 3 years if business use does not change by more than 20%.
How the 90-day logbook works
Record every business and private trip for at least 90 consecutive days, including date, distance and purpose. Divide business kilometres by total kilometres for the sample period. IRD says that result can generally be used for up to three years while the pattern of use does not change by more than 20%.
Keep opening and closing odometer readings and evidence that the sample is representative. If you have no adequate logbook, IRD's published guidance uses 25% of actual running costs as a conservative limit unless other records establish a different proportion.
Kilometre rate vs actual costs
| Method | Calculation | Records |
|---|---|---|
| Kilometre rate | IRD Tier 1 and Tier 2 rates × business kilometres | Odometer and trip/logbook evidence |
| Actual costs | Eligible costs × business-use percentage | Invoices, receipts, depreciation and logbook evidence |
Use the detailed IRD kilometre-rate calculator for the current rate table and Tier 1/Tier 2 breakdown.
Frequently asked questions
How long must an NZ vehicle logbook run?
IRD accepts a representative logbook kept for at least 90 consecutive days. It can generally support the business-use percentage for up to three years if use does not change by more than 20%.
What happens if I do not keep a logbook?
For the actual-cost method, IRD says the claim may be limited to 25% of vehicle running costs unless other records support a different business-use proportion.
Does this planner choose my tax method for me?
No. It compares estimates only. Eligibility, depreciation, record quality, GST and the requirement to keep using a chosen method for a vehicle can affect the final claim.
Official source: Inland Revenue — vehicle expenses. Checked July 2026.
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