Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Straight-line planning value, not resale appraisal or jurisdiction-specific tax depreciation.
Example Calculation
- Purchase cost: 1000 currency
- Residual value: 100 currency
- Useful life: 10 years
- Elapsed age: 4 years
Cost 1000, residual 100 and ten-year life give annual depreciation 90; after four years, modeled value is 640.
Frequently asked questions
How do I use this calculator?
Enter purchase cost, residual value, useful life, elapsed age. The result updates automatically. Use Reset to restore the example values.
What method does it use?
annual depreciation=(cost−residual)/life; book value=max(residual,cost−annual × age).. Straight-line planning value, not resale appraisal or jurisdiction-specific tax depreciation.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.