{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"depreciation"},"result":{"entity_type":"calculator","id":"depreciation","calculator_id":"depreciation","canonical_url":"https://tttkmbb.com/finance/depreciation","name":"Depreciation Calculator","title":"Depreciation Calculator – Straight-Line, Declining-Balance, Double-Declining and Sum-of-Years-Digits Schedules","category":"finance","category_name":"Finance","tool_name":"calculate_depreciation","featured_mcp_tool":false,"description":"Computes an asset's depreciation expense for a chosen year, the accumulated depreciation and the book value, plus the full year-by-year schedule, using the straight-line, 150 % declining-balance, double-declining-balance or sum-of-the-years'-digits method.","use_when":"You need book (financial-statement) depreciation of equipment, vehicles or buildings over their useful life, or want to compare accelerated methods with straight-line.","do_not_use_when":"You need US tax depreciation under MACRS with its conventions and class lives (IRS Publication 946 tables), or units-of-production depreciation.","inputs":[{"name":"cost","label":"Asset cost","type":"number","required":true,"max":1000000000000,"exclusive_min":0,"description":"Purchase price plus costs to put the asset in service.","example":10000},{"name":"salvage_value","label":"Salvage (residual) value","type":"number","required":false,"default":0,"min":0,"max":1000000000000,"description":"Estimated value at the end of the useful life; must be below cost.","example":1000},{"name":"useful_life_years","label":"Useful life","type":"integer","unit":"years","required":true,"min":1,"max":40,"description":"Years over which the asset is depreciated.","example":5},{"name":"method","label":"Method","type":"enum","required":false,"default":"straight_line","values":[{"value":"straight_line","label":"Straight-line","aliases":["sl","straight","linear"]},{"value":"declining_balance","label":"150 % declining balance (switching to straight-line)","aliases":["db","150db","150%"]},{"value":"double_declining","label":"Double (200 %) declining balance (switching to straight-line)","aliases":["ddb","200db","double declining balance","200%"]},{"value":"sum_of_years_digits","label":"Sum-of-the-years'-digits","aliases":["syd","sum of years digits","sum-of-years-digits"]}],"description":"Depreciation method.","example":"straight_line"},{"name":"year","label":"Year","type":"integer","required":false,"default":1,"min":1,"max":40,"description":"Year of the asset's life to report (1 = first year).","example":3}],"outputs":[{"name":"depreciation_for_year","label":"Depreciation for the year","type":"number","decimals":2,"description":"Expense recognised in the requested year."},{"name":"accumulated_depreciation","label":"Accumulated depreciation","type":"number","decimals":2,"description":"Total depreciation through the end of that year."},{"name":"book_value_end_of_year","label":"Book value at year end","type":"number","decimals":2,"description":"cost − accumulated_depreciation."},{"name":"depreciable_base","label":"Depreciable base","type":"number","decimals":2,"description":"cost − salvage_value."},{"name":"annual_rate_percent","label":"Rate applied","type":"number","unit":"%","decimals":2,"description":"Straight-line 100/life of the base; declining balance 150/life or 200/life of the opening book value; SYD the year's fraction of the base."},{"name":"method_used","label":"Method","type":"string","decimals":4,"description":"Name of the method applied."},{"name":"schedule","label":"Depreciation schedule","type":"list","decimals":2,"description":"One row per year: year, depreciation, accumulated, book_value (at most 40 rows)."}],"input_schema":{"type":"object","properties":{"cost":{"description":"Purchase price plus costs to put the asset in service.","type":"number","maximum":1000000000000,"exclusiveMinimum":0,"examples":[10000]},"salvage_value":{"description":"Estimated value at the end of the useful life; must be below cost.","type":"number","minimum":0,"maximum":1000000000000,"default":0,"examples":[1000]},"useful_life_years":{"description":"Years over which the asset is depreciated. 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Unit: %.","type":"number","x-unit":"%"},"method_used":{"description":"Name of the method applied.","type":"string"},"schedule":{"description":"One row per year: year, depreciation, accumulated, book_value (at most 40 rows).","type":"array"}}},"formula":"base = cost − salvage. Straight-line: D_y = base / life. Declining balance: D_y = max(book_{y−1} × f/life, (book_{y−1} − salvage)/(life − y + 1)) with f = 1.5 or 2, never below salvage. Sum-of-years-digits: D_y = base × (life − y + 1) / (life × (life + 1) / 2).","method":"Full-year convention (the asset is placed in service at the start of year 1). Declining-balance methods switch to straight-line over the remaining life when that gives a larger deduction, as in IRS Publication 946, which also guarantees the book value ends exactly at salvage.","sources":[{"name":"IRS Publication 946 – How To Depreciate Property","url":"https://www.irs.gov/publications/p946","type":"government","retrieved_at":"2026-09-24"},{"name":"Investopedia – Double-Declining Balance (DDB) Depreciation Method","url":"https://www.investopedia.com/terms/d/double-declining-balance-depreciation-method.asp","type":"reference","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Depreciation","url":"https://en.wikipedia.org/wiki/Depreciation","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"10,000 cost, 1,000 salvage, 5 years, straight-line, year 3","inputs":{"cost":10000,"salvage_value":1000,"useful_life_years":5,"method":"straight_line","year":3},"expected":{"depreciation_for_year":1800,"accumulated_depreciation":5400,"book_value_end_of_year":4600,"depreciable_base":9000,"annual_rate_percent":20,"method_used":"Straight-line"},"url":"https://tttkmbb.com/api/v1/calculate/depreciation?cost=10000&salvage_value=1000&useful_life_years=5&method=straight_line&year=3"},{"name":"10,000 cost, 1,000 salvage, 5 years, double-declining, year 2","inputs":{"cost":10000,"salvage_value":1000,"useful_life_years":5,"method":"double_declining","year":2},"expected":{"depreciation_for_year":2400,"accumulated_depreciation":6400,"book_value_end_of_year":3600,"annual_rate_percent":40,"schedule":[{"year":1,"depreciation":4000,"accumulated":4000,"book_value":6000},{"year":2,"depreciation":2400,"accumulated":6400,"book_value":3600},{"year":3,"depreciation":1440,"accumulated":7840,"book_value":2160},{"year":4,"depreciation":864,"accumulated":8704,"book_value":1296},{"year":5,"depreciation":296,"accumulated":9000,"book_value":1000}]},"url":"https://tttkmbb.com/api/v1/calculate/depreciation?cost=10000&salvage_value=1000&useful_life_years=5&method=double_declining&year=2"}],"faq":[{"q":"Why does double-declining balance stop early?","a":"It applies a fixed rate to a shrinking book value and never depreciates below salvage, so the final years are capped (296 in year 5 of the example) or switch to straight-line."},{"q":"Which method should I use?","a":"Straight-line is the default for financial statements; accelerated methods front-load expense for assets that lose value quickly. Tax depreciation follows separate rules (MACRS in the US)."}],"tags":["depreciation","straight line depreciation","double declining balance","sum of years digits","book value","depreciation schedule"],"related":[{"calculator_id":"npv","reason":"Appraise the asset purchase with discounted cash flows."},{"calculator_id":"payback-period","reason":"Time to recover the asset's cost."},{"calculator_id":"percentage-change","reason":"Percent fall in value between two years."}],"links":{"html":"https://tttkmbb.com/finance/depreciation","markdown":"https://tttkmbb.com/finance/depreciation.md","json":"https://tttkmbb.com/finance/depreciation.json","api":"https://tttkmbb.com/api/v1/calculate/depreciation","schema":"https://tttkmbb.com/api/v1/calculators/depreciation","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:59:09Z","next_actions":[{"tool":"run_calculator","calculator_id":"depreciation","reason":"Run Depreciation Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/finance/depreciation.md"}}