Calculate a depreciation schedule by straight-line, declining balance, double declining, sum-of-years' digits or units of production, with book value.
更新日 検証済みの例：9
Straight-line writes off $9,000.00 in the first year and $45,000.00 over 5 years, leaving a book value of $5,000.00.
| 年 | 減価償却 | Accumulated | Book value |
|---|---|---|---|
| 1 | $9,000.00 | $9,000.00 | $41,000.00 |
| 2 | $9,000.00 | $18,000.00 | $32,000.00 |
| 3 | $9,000.00 | $27,000.00 | $23,000.00 |
| 4 | $9,000.00 | $36,000.00 | $14,000.00 |
| 5 | $9,000.00 | $45,000.00 | $5,000.00 |
Depreciation spreads an asset's cost, less its expected salvage value, over its useful life. Straight-line charges the same amount every year, (cost − salvage) ÷ life. Declining balance applies a fixed rate to the book value left, so charges fall year by year; double declining uses 2 ÷ life. Sum-of-years' digits weights year t by (n − t + 1) ÷ (n(n + 1)/2), and units of production charges a fixed amount per unit made.
With the defaults, an asset costing 50,000 with a salvage value of 5,000 and a 5-year life, straight-line depreciation is 9,000 a year, 20% of the depreciable amount. Double declining balance would charge 20,000 in the first year and sum-of-years' digits 15,000; every method writes off the same 45,000 in total.
These are book-accounting methods. US tax depreciation follows MACRS recovery periods and conventions in IRS Publication 946, which this schedule does not apply.
照合元：Microsoft SLN documentation example: SLN(30000, 7500, 10) = 2,250
照合元：Microsoft SYD documentation example: year 1 = 4,090.91, year 10 = 409.09
照合元：Microsoft DDB documentation example: first year 480.00, tenth year 22.12
照合元：Python decimal: 4000, 2400, 1440, then SL 2160/2 = 1080 beats DDB 864 in years 4–5
Subtract the salvage value from the cost and divide by the useful life in years. An asset costing 50,000 with a 5,000 salvage value and a 5-year life depreciates by (50,000 − 5,000) ÷ 5 = 9,000 a year, leaving a book value of 5,000. Excel's SLN function does the same: SLN(30000, 7500, 10) = 2,250.
Multiply the start-of-year book value by 2 ÷ life, and stop when the book value reaches salvage. For 50,000 over 5 years the rate is 40%: 20,000 in year 1, then 12,000, 7,200 and 4,320, and 1,480 in year 5 to land on the 5,000 salvage. With zero salvage the rate never reaches zero, so companies switch to straight-line when it gives a larger charge.
IAS 16 names straight-line, diminishing balance and units of production, and asks for the method that reflects how the asset's benefits are used up. It does not list sum-of-years' digits, and paragraph 62A prohibits methods based on the revenue an asset generates.
Most business property uses MACRS (IRS Publication 946): cars are 5-year property, office furniture 7-year, residential rental buildings 27.5 years and nonresidential real property 39 years. Personal property is depreciated at 200% declining balance switching to straight-line, with a half-year convention unless more than 40% is placed in service in the last quarter (mid-quarter), and real property uses mid-month.
For 2025, US businesses can expense up to $2,500,000 of qualifying property under Section 179, reduced once purchases exceed $4,000,000; for 2026 the figures are $2,560,000 and $4,090,000 (IRS Publication 946). Bonus depreciation is 100% for qualifying property acquired and placed in service after January 19, 2025.
精度は入力値と計算方法の前提に依存します。十進演算には有効数字50桁を使いますが、推定、数値計算手法、元データの精度はそれより低い場合があります。表示の丸め処理でこれらの制約がなくなるわけではありません。 独立した出典の解答と照合した計算例：9。 例えば、「Straight-line 30,000 cost, 7,500 salvage, 10 years」はMicrosoft SLN documentation example: SLN(30000, 7500, 10) = 2,250と照合しています。
Microsoft Support — SLN, DDB, DB and SYD functions; IRS Publication 946 — How to Depreciate Property.
計画の参考用です。金融機関、税務当局、市場は独自の丸め方、手数料、規則を適用します。契約などの前に該当機関へ金額を確認してください。
この計算機には、独立した出典の解答を使った計算例が 9 件あります。テストに組み込まれており、ここでも実行できます。
Calculate the break-even point in units and sales revenue from fixed costs, price and variable cost, plus the volume needed for a target profit.
Calculate enterprise value, equity value and value per share with a DCF: projected free cash flows plus a Gordon-growth terminal value.
Calculate NPV, IRR, modified IRR, payback and discounted payback for a series of periodic cash flows, with the NPV profile across rates.
Calculate a monthly car lease payment from the price, residual value and money factor or APR, split into depreciation, finance charge and tax.