Assumptions. A fixed-rate, fully-amortising loan with equal monthly payments: the standard structure for mortgages and personal loans. It excludes fees, insurance, taxes and any variable-rate changes, which your lender's offer will set out.
A loan is one line on your balance sheet.
Manticore Finance tracks your debts next to your assets, so you see net worth, not just what you own, but what you owe against it, and how that changes over time.
How a loan payment is calculated
With a fixed-rate amortising loan, every monthly payment is the same, but its split shifts over time: early on, most of it is interest and only a little pays down the balance; later, as the balance shrinks, more of each payment is principal. The fixed payment is set so the loan reaches exactly zero at the end of the term.
The formula is M = P · i / (1 − (1 + i)−N), where P is the amount borrowed, i is the monthly rate (annual ÷ 12) and N is the number of monthly payments.
How to use it
Enter the amount, the rate you've been quoted, and the term. Watch the total interest as you change the term: a shorter term means a higher monthly payment but far less interest over the life of the loan, because the balance is cleared sooner.