Mortgage / Loan Calculator
Find out your monthly payment with equal principal-and-interest amortization.
Estimated using standard amortization — each payment stays the same but the principal/interest mix shifts over time. Actual figures depend on your lender.
How is a loan payment calculated?
Most mortgages and installment loans use "amortized" payments — the total monthly payment stays fixed for the life of the loan, but the mix shifts over time: early payments are mostly interest, later payments are mostly principal. This keeps your monthly budget predictable even though the loan balance is shrinking unevenly.
The formula looks intimidating, but the idea is simple: it spreads the total principal plus interest evenly across every payment so each installment is identical. This tool runs the formula for you — just enter the loan amount, annual rate, and term.
Why loan term length changes the math so much
Stretching a loan from 15 to 30 years roughly cuts the monthly payment, which is why longer terms look appealing on the surface — but doubling the term doesn't just double the interest, it can more than double it, since the balance stays higher for longer and accrues interest against that higher balance for twice as many months. Running the same loan amount through this calculator at a few different term lengths side by side is often the fastest way to see the real tradeoff between monthly affordability and total cost.
Frequently asked questions
Why is the total repaid so much more than the loan amount?
The difference is interest. A longer term lowers your monthly payment but significantly increases total interest paid, since interest accrues on the remaining balance every month. On the same loan amount, a 30-year term can cost tens of thousands more in total interest than a 15-year term — which is why this tool breaks out "total interest" separately.
How much can I save by paying off my loan early?
Because interest is calculated on the remaining balance, extra payments — especially early in the loan — reduce future interest meaningfully. The earlier you pay down principal, the more you save. Check for prepayment penalties first, since some lenders charge a fee for paying off a loan ahead of schedule.
What's the difference between amortized and equal-principal repayment?
Amortized repayment (used by this tool) keeps the total monthly payment constant. Equal-principal repayment keeps the principal portion constant instead, so interest — and the total payment — decreases every month. Equal-principal pays less total interest overall but starts with a higher payment, so it suits borrowers with more cash flow upfront.
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📖 Related guide
Compare monthly payment, total interest, and loan term before judging a mortgage or loan scenario.
Read the mortgage guide →Monthly payment vs total cost
A lower monthly payment from a longer term usually means more interest over the full schedule. Compare payment, total interest, and total amount repaid side by side before preferring the smallest payment alone.
This page estimates a standard amortising (level-payment) loan at a fixed rate. Real offers may add fees, insurance, variable rates, or prepayment rules. Use the lender’s official quote for decisions. Calculations stay on your device.