Loan & Mortgage Calculator
Calculate monthly payments, total interest, and amortisation for any loan or mortgage.
Finance tools · Free · AI-powered
About the Loan & Mortgage Calculator
A loan calculator computes your monthly payment, total interest, and amortisation schedule based on the loan amount, interest rate, and term. Use it for mortgages, auto loans, personal loans, or any fixed-rate installment debt.
The hidden cost of long terms. Lenders love long terms because they collect more interest. A 30-year $300k mortgage at 7% costs $419k in interest over the life of the loan — more than the house. The same loan over 15 years costs $185k in interest. Doubling the term more than doubles the interest cost.
Extra payments shrink the interest bill. This calculator shows the standard schedule; to test paying extra each month, use the extra-payment field in our mortgage calculator. On a $300k, 30-year loan at 7%, an extra $200 a month pays it off about seven years early and saves well over $100k in interest.
APR vs interest rate. Lenders quote both. Interest rate is what you pay on the loan balance. APR includes lender fees and is the true cost — always compare APR across offers.
When to refinance. A common rule of thumb: refinancing can make sense when the new rate is at least 0.75% lower than your current rate AND you'll stay in the loan long enough to recover closing costs. Use the calculator to compare scenarios. This is general education, not financial advice.
How to use it
- Enter the loan amount. Type the principal you'll borrow.
- Set the interest rate. Use the APR from your loan offer.
- Choose the term. Set how many years to repay.
- Review the monthly payment. Confirm it fits your budget — under 28% of gross income for housing.
- Try shorter terms. Compare 15- vs 30-year scenarios to see total interest saved.
Frequently asked questions
How is the monthly payment calculated in this loan calculator?
It uses the standard amortization formula P × r(1+r)^n ÷ ((1+r)^n − 1), where r is the annual rate ÷ 12 and n is the term in months; at 0% the payment is simply the loan amount ÷ n. The default $300,000 at 7% for 30 years works out to $1,995.91 a month.
How much more interest does a 30-year loan cost than a 15-year loan in the loan calculator?
On the default $300,000 at 7%, a 30-year term costs about $418,527 in interest versus about $185,367 over 15 years — roughly 2.3 times as much. The 15-year payment is higher, $2,696.48 versus $1,995.91 a month, so check that it fits your budget.
Does the loan calculator's monthly payment include taxes, insurance or lender fees?
No — the payment is principal and interest only. For a mortgage, add property tax, homeowners insurance, PMI and any HOA dues; and if you enter an APR that already bakes in fees, the payment shown will be slightly higher than your actual note-rate payment.
Can I add extra monthly payments in the loan calculator?
Not in this tool — it shows the scheduled payment and amortization only. For a 10-, 15-, 20- or 30-year loan, the Mortgage Calculator's extra-payment field shows how much interest and time an extra amount each month saves.
Why does most of my early payment go to interest in the loan calculator's amortisation chart?
Each month's interest is the remaining balance × APR ÷ 12, and the balance is highest at the start. On the default loan, the first month's interest is $1,750 of the $1,995.91 payment; as the balance falls, more of each payment goes to principal, which is why the principal-paid line steepens later in the term.
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