NZ depreciation calculator and IRD rate finder
Search all 3,023 general depreciation rates in Inland Revenue's IR265 (March 2026), then work out depreciation using diminishing value (DV) or straight line (SL). It handles part-year months (part-months count as whole months), business and private use, and the 20% Investment Boost for new assets. You get a year-by-year schedule with the adjusted tax value.
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Rate finderCalculatorHow it worksExamplesFAQ
1. Find your asset's IRD depreciation rate
If your asset is listed in your industry category, use that rate. If it isn't, use the asset category (shown as "asset category"). If neither lists it, IR265 explains how to use the default class or apply for a provisional rate.
2. Work out depreciation
How NZ depreciation is worked out
- Diminishing value: adjusted tax value × DV rate. In the first year the adjusted tax value is the cost.
- Straight line: cost × SL rate each year, until the adjusted tax value reaches $0 (the last year is whatever is left).
- Part year: depreciation × months used ÷ 12. Part-months count as whole months.
- Private use: depreciation × business-use %. The adjusted tax value still falls by the full depreciation amount.
- Investment Boost: for eligible new assets, deduct 20% of the cost in the year the asset is first available for use. Then depreciate the remaining 80% as if it were the full cost.
- Low-value assets: assets costing less than $1,000 (bought on or after 17 March 2021) can usually be deducted in full straight away.
Examples (from Inland Revenue)
| Example | Result |
|---|---|
| Commercial espresso machine $10,000, coffee makers DV 30%, full year | $3,000; adjusted tax value $7,000 |
| Same machine, years 2 to 4 | $2,100, $1,470, $1,029 (value $2,401) |
| Bought 20 May, 31 March balance date: 11 months | $3,000 × 11 ÷ 12 = $2,750 |
| 70% business use | $2,750 × 70% = $1,925 |
| Computer terminal $1,200, SL 21%, years 1 to 5 | $252 × 4, then $192 |
| Terminal used 6 months, 40% business use | $126, then $50.40 |
| Dishwasher $1,200, SL 13.5% (IR265 example) | $162 a year; year 8 $66 |
| Deep fryer $2,500 with Investment Boost | $500 deduction; depreciate $2,000 |
| Taxi $45,000, 50% private use, Investment Boost | $4,500 deduction; depreciate $36,000 |
FAQ
How do I find the IRD depreciation rate for an asset?
Look the asset up in Inland Revenue’s IR265 general depreciation rates. Use your industry category if it lists the asset, otherwise the asset category. Each entry gives an estimated useful life, a diminishing value (DV) rate and a straight-line (SL) rate. The finder on this page searches all 3,023 IR265 entries.
Should I use diminishing value or straight line?
Either is allowed for most assets. You choose per asset and can change method from year to year. DV gives bigger deductions early on. SL gives the same deduction each year until the asset is written off. Pools must use DV.
How do I work out depreciation if I bought the asset partway through the year?
Multiply the full-year depreciation by the number of months you owned and used the asset, divided by 12. Part-months count as whole months. For example, an asset bought on 20 May with a 31 March balance date has 11 months.
What is the adjusted tax value?
It’s the cost less all depreciation claimed so far. Next year’s DV depreciation is worked out on this value. For an asset with private use, the value falls by the full depreciation amount, even though you only claim the business share.
How does Investment Boost work with depreciation?
For eligible new assets first available for use on or after 22 May 2025, you deduct 20% of the cost in that year. Then you depreciate the remaining 80% as if it were the full cost. With private use, you claim the business share of the 20% too.
Can I claim an asset under $1,000 straight away?
Usually, yes. Assets bought on or after 17 March 2021 that cost less than $1,000 (excluding GST if you’re registered) can be deducted in full as low-value assets. Different rules apply when you buy several items from the same supplier at the same time.
Sources (checked 17 Oct 2026): Inland Revenue General depreciation rates (IR265, March 2026); Inland Revenue Work out diminishing value depreciation and straight-line depreciation; Inland Revenue Depreciation (low-value assets); Inland Revenue Investment Boost examples.
General information, not tax advice. This doesn't cover pooling, disposals (depreciation recovery or loss on sale), provisional rates, or pre-2005 rates. Rates were parsed from the IR265 PDF. Check the rate in IR265 before you file.