Car Logbook Tax Deduction Calculator 2026–27
Two ways to claim your work driving, and they rarely give the same answer. This calculator works out your logbook deduction for the 2026–27 income year and compares it against the ATO's 91 cents per kilometre alternative for the same year. If you are still lodging your 2025–26 return, the rate for that year is 88 cents — the table below gives both.
| Tax Saving (Logbook) | $0 |
| Business Use % | 0% |
| Cents Per Km Deduction (91c, 2026–27) | $0 |
| Tax Saving (Cents/km) | $0 |
| Better Method | — |
| Extra Saving (Better Method) | $0 |
Logbook Method vs Cents Per Km
There are two ATO-approved methods for claiming car expenses as a tax deduction. Choosing the right one can significantly affect your refund.
Logbook Method
The logbook method allows you to claim the business-use percentage of all actual car expenses:
- Fuel and oil
- Insurance
- Registration
- Servicing and repairs
- Depreciation (decline in value)
- Interest on a car loan
- Car wash costs
You must keep a logbook for at least 12 continuous weeks showing the purpose of each trip (business or private). The logbook is valid for 5 years unless your circumstances change significantly.
A worked example
$9,000 of running costs at 40% business use is a logbook claim of $3,600. The same 5,000 work-related kilometres claimed at the 2026–27 rate of 91c comes to $4,550. Cents per km wins here, and at a 30% marginal rate the difference is worth $285 in the hand.
Cents Per Kilometre Method
The cents per km method is simpler — you claim a flat rate for every work-related kilometre, up to a maximum of 5,000 kilometres per car. No logbook is required but you must be able to demonstrate how you worked out your work-related kilometres (e.g., diary, calendar records). This is ideal for lower-mileage drivers or those without a complete logbook.
The rate depends on which income year you are claiming. Both are live right now: 2026–27 is the year you are driving through and the one this calculator uses, and 2025–26 is the return still being lodged this spring.
| Income year | Rate per kilometre | Maximum claim (5,000 km) |
|---|---|---|
| 2026–27 — the year in progress (used above) | 91 cents | $4,550 |
| 2025–26 — the return being lodged now | 88 cents | $4,400 |
The calculator above uses the 2026–27 rate of 91 cents — a base of 89c plus a one-off 2c uplift — because that is the year you are driving through. If you are still lodging your 2025–26 return instead, that year's rate is 88 cents, so 4,000 work kilometres is $3,520 rather than $3,640.
| Feature | Logbook Method | Cents Per Km |
|---|---|---|
| Cap on deduction | None | 5,000 km per car ($4,550 max at 91c) |
| Records required | 12-week logbook + receipts | Business km records only |
| Expenses covered | All actual costs | All-inclusive per km rate |
| Best for | High km or expensive cars | Low km or simpler claims |