Marine Annual Ownership Cost Calculator
Add your own yearly boat expenses and see the monthly equivalent and each item’s share.
A QUICK WALKTHROUGH
How to use this tool
- Enter a currency label and one to 100 named annual expense amounts.
- Use the same currency for every amount; enter your own records or estimates.
- Calculate, then copy or download the input and result report.
Calculation
Annual total = sum of entered amounts. Monthly equivalent = annual total ÷ 12. Item share = amount ÷ annual total × 100; shares are undefined when the total is zero.
Scope and precision
Enter annual amounts in one currency. This tool does not estimate depreciation, prices, taxes, financing or future costs, or convert currency. The monthly figure is an even allocation, not a payment schedule. JavaScript binary floating-point arithmetic can round decimal inputs and results; the report keeps raw inputs and shows computed numbers without fixed currency rounding. It rejects overflow, a positive input becoming zero, a positive sum addend disappearing, and positive monthly or percentage values becoming zero.
Local processing
Calculation and report creation happen in your browser; inputs are not uploaded.
GOOD TO KNOW
Common questions
Are expense amounts or depreciation supplied?
No. Start with a blank row and supply all annual amounts yourself. No depreciation model is included.
What happens with a zero annual total?
The annual and monthly totals are zero. Every percentage is explicitly undefined because division by zero has no valid share.