Logbook vs cents per km calculator (car expenses)
Which car expense method gives you the bigger deduction? With the logbook method, you claim your business-use percentage of all your car costs: fuel, rego, insurance, servicing, interest and decline in value. With the cents per km method, you claim 91c per km for 2026-27 (88c for 2025-26 and 2024-25), up to 5,000 km per car. Enter your logbook figures and car costs to compare the two side by side. Figures reproduce the ATO's examples.
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CalculatorHow each method worksExamplesFAQ
How each method works
- Cents per km: business km × the rate (91c for 2026-27, 88c for 2025-26 and 2024-25, 85c for 2023-24), up to 5,000 km per car. You don't need receipts, but you must be able to show how you worked out your km, for example with diary records.
- Logbook: keep a logbook for at least 12 continuous weeks that's representative of your travel, and record odometer readings. Business-use % = business km ÷ total km × 100. Claim that % of all your car expenses, including decline in value, but not the purchase price or loan principal. A logbook is valid for 5 years.
- You can use a different method for each car and change methods from year to year. Car expenses go in your return in whole dollars, with cents dropped.
Examples (ATO)
| Example | Claim |
|---|---|
| Tim: 6,600 of 11,000 km = 60%; expenses $9,000 × 60% | $5,400 |
| Theodore: 4,100 ÷ 6,500 = 63%; $1,140 + $2,445.20 decline in value = $3,585.20 × 63% = $2,258.67 | $2,258 |
| Joanne, 2024-25: 5,300 work km, capped at 5,000 × $0.88 | $4,400 |
| 2025-26: 2,514 km × $0.88 = $2,212.32 | $2,212 |
FAQ
Is the logbook method or cents per km better?
Cents per km is simpler, but it’s capped at 5,000 km, which is $4,550 at 91c for 2026-27. The logbook method usually wins if you drive a lot for work or have a more expensive car, because you claim your business-use percentage of every car cost, including decline in value.
How do I work out my logbook business-use percentage?
Divide the business kilometres in your 12-week logbook period by the total kilometres in the same period and multiply by 100. In the ATO example, 4,100 business km out of 6,500 km is 63%.
What is the cents per km rate for 2026-27?
91 cents per km for 2026-27, up from 88 cents for 2025-26 and 2024-25. You can claim up to 5,000 business km per car, so the most you can claim is $4,550 per car.
Can I switch between the logbook and cents per km methods?
Yes. You can change methods from one year to the next, and use a different method for each car. A logbook stays valid for up to 5 years, provided it still reflects how you use the car.
What car expenses can I include with the logbook method?
Fuel or charging, registration, insurance, servicing and repairs, interest on a car loan or lease payments, and decline in value. You can’t include the purchase price or loan repayments of principal.
Sources (checked 17 Oct 2026): ATO Logbook method; D1 Work-related car expenses 2025; Cents per kilometre method; Expenses for a car you own or lease.
General information, not tax advice. This applies to cars (not vans or utes that carry a tonne or more), for sole traders, partnerships and employees. Work out decline in value separately (the car cost limit applies). If you're registered for GST, use expenses excluding the GST you claim back. Employees can only claim work-related travel, not travel between home and work.