depreciation_calculator
shallownz.co.calculate/calculator · Verify this server
Depreciate an asset by straight line or diminishing value, with a year by year schedule. Use for: 'how is depreciation calculated', 'straight line vs diminishing value', 'depreciation schedule', 'book value after 3 years', 'work out depreciation on equipment'. THE TWO METHODS DIVERGE SHARPLY ON THE SAME ASSET. Straight line spreads the deduction evenly across the useful life. Diminishing value applies the rate to the REDUCING book value, so it front-loads the deduction heavily and never reaches zero on its own. Which is better depends entirely on when the owner wants the deduction, so the year by year schedule is the useful part of this answer rather than the first year figure. Show the schedule. additional_costs are capitalised into the cost base, which is where delivery and installation belong. salvage_value acts as a floor under both methods, and the last year of a straight line life takes only what is left, so rounding cannot push the book value below it. ONE IMPORTANT LIMIT, AND IT MATTERS. This is the ARITHMETIC of the two methods on a rate you supply. It is NOT a lookup of Inland Revenue's prescribed rates, which vary by asset class and are published in the IRD depreciation rate finder. If someone needs to know the right RATE for a particular asset, send them to that finder. DO NOT INVENT A RATE to feed this tool and present the output as their tax position. Args: initial_cost: Purchase price of the asset. method: straight_line or diminishing_value. additional_costs: Costs capitalised in, such as delivery or installation. salvage_value: Expected residual value. A floor under both methods. useful_life_years: Years of life. Required for straight line. annual_rate_pct: Rate per year. Required for diminishing value. years_to_schedule: Years to show. Defaults to the life, or ten. Returns: The cost base, the depreciable amount, the first year charge, the total charged, the closing book value and the full year by year schedule.
1 trials · measured 40 days ago
depreciation_calculator scores 100.0/100 on Vouch's measured behaviour index, from 1 real invocation trials against nz.co.calculate/calculator, measured 11 Sept 2026 under methodology v0.2.0. Every measured component scored 100.
Component breakdown
| Component | Weight | Value |
|---|---|---|
| Reliability | 35% | not applicable |
| Schema integrity | 25% | 100.0 |
| Failure behaviour | 15% | not applicable |
| Latency | 15% | not applicable |
| Concurrency | 10% | not applicable |
Tool details
- Transport
- remote
- Credential class
- self-provisionable
- Input schema
- not declared
- Output schema
- not declared
- Side-effect classification
- unclassified
Score history
| Day | Score | Tier | Methodology |
|---|---|---|---|
| 2026-09-11 | 100.0 | shallow | v0.2.0 |
Probe evidence
| Probe | Outcomes |
|---|---|
| schema_integrity | pass: 1 |
Raw request/response logs are not archived yet — the outcome counts above are drawn directly from every recorded trial.
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