Boat Loan Calculator
Inputs
Tab to move between fields
Results
Monthly Payment
$427.33
≈ 8 tanks of gas
Total Cost
$60,279.16
≈ 5 years of state college
Identify Input Parameters
4 parameters
= Boat Price = 45000, Down Payment = 9000, Interest Rate = 7.5, Loan Term = 10
= 4 input(s) provided
Calculate Monthly Payment
Monthly Payment
= 427.33
= $427.33
Calculate Total Cost
Total Cost
= 60279.16
= $60,279.16
Calculate Total Interest
Total Interest
= 15279.16
= $15,279.16
Calculate Loan Amount
Loan Amount
= 36000
= $36,000
Amortising loan payment
- 1.Convert the annual rate to a monthly rate
Payments are monthly, so every term in the formula has to be expressed per month.
- 2.Count the payments
The number of monthly payments over the whole term.
- 3.Solve for the level payment
This comes from setting the present value of all n equal payments equal to the amount borrowed, then solving for the payment. The (1+i)ⁿ − 1 in the denominator is the sum of a geometric series — the same series that drains a pension or decays a drug in plasma, which is why one formula family serves calculators across several hubs.
Simon Stevin published the first printed interest tables, including the present value of an annuity — the relationship this payment formula inverts. Until then such tables were guarded as trade secrets by lenders.