Paying back a fixed amount periodically until the loan is paid off. Common for mortgages, auto loans, student loans, and personal loans.
Paying back a single lump sum (principal plus accumulated interest) when the loan matures, with no payments in between.
A bond is bought at a discount today and pays back a predetermined face value at maturity. Enter the amount due at maturity to find what it is worth now.
A loan calculator is a tool that helps you understand the true cost of borrowing money. Whether you are taking out a mortgage, financing a car, consolidating debt, funding a business, or investing in a bond, this calculator shows you exactly what a loan will cost over its lifetime. It handles the three fundamental structures that almost every loan falls into: amortized loans that you pay back in regular installments, deferred payment loans that you repay in a single lump sum at the end, and bonds, where a fixed face value is paid back at maturity. Enter your numbers, choose your structure, and the calculator returns your payment, total interest, and a full schedule in seconds.
Understanding how a loan is calculated puts you in control. It lets you compare offers, see how the interest rate and term change your costs, and decide how much you can realistically afford to borrow. The sections below explain each loan type, the math behind the results, and the key concepts - interest rate, compounding, and amortization - that determine what you ultimately pay.
An amortized loan is the most common type of consumer loan. You borrow a sum of money and pay it back in equal periodic installments - usually monthly - over a fixed term. Each payment is split between interest (the cost of borrowing) and principal (the amount that reduces your balance). Early in the loan, most of each payment goes toward interest because the balance is high; as the balance shrinks, a larger share goes toward principal. Mortgages, auto loans, student loans, and personal loans are almost always amortized.
The amortized loan tab on this calculator asks for the loan amount, term (in years and months), annual interest rate, how often interest compounds, and how often you make payments. It returns your fixed payment per period, the total of all payments, and the total interest paid, along with a complete amortization schedule showing the breakdown of every payment.
A deferred payment loan requires no payments during the term. Instead, interest accrues and compounds on the balance, and the entire amount - original principal plus all accumulated interest - is repaid in a single lump sum when the loan matures. This structure is sometimes used for short-term business financing, certain student loan arrangements during school, and bridge loans. Because interest compounds on a growing balance with nothing being paid down, the final amount due can be substantially larger than the original loan.
The deferred payment tab asks for the loan amount, term, interest rate, and compounding frequency, then returns the total amount due at maturity and the total interest that accumulated.
A bond works in the opposite direction from a typical loan. With a bond, a fixed amount - the face value or par value - is promised at a future maturity date. The question is: how much should you pay for that bond today? The calculator discounts the future face value back to the present using the interest rate (the yield), telling you the price you should pay now so that it grows to the face value at maturity. This is the foundation of how zero-coupon bonds and many fixed-income investments are priced.
The bond tab asks for the predetermined amount due at maturity, the term, the interest rate, and the compounding frequency, then returns the amount you would receive (or pay) when the loan starts and the total interest earned over its life.
The amortized loan payment is calculated with the standard amortization formula, which ensures that a constant payment exactly pays off the balance over the term:
Payment = P × i ÷ [ 1 − (1 + i)−n ]
Here P is the loan amount (principal), i is the interest rate per payment period, and n is the total number of payments. For a $100,000 loan at 6% interest compounded monthly and paid back monthly over 10 years, the periodic rate is 0.5% (6% ÷ 12), the number of payments is 120, and the resulting monthly payment is about $1,110.21. Over the life of that loan you would pay roughly $133,224.60 in total, of which $33,224.60 is interest.
For a deferred payment loan, no amortization is involved - the balance simply compounds. The amount due at maturity is:
Amount Due = P × (1 + r ÷ m)m × t
where r is the annual rate, m is the number of compounding periods per year, and t is the term in years. The same $100,000 at 6% compounded annually for 10 years grows to $179,084.77 - meaning $79,084.77 of interest. For a bond, the formula is rearranged to solve for the present value, dividing the face value by the same growth factor.
The interest rate is the single most important factor in the cost of a loan. It represents the percentage of the outstanding balance charged by the lender for the use of their money. Even small differences in rate can translate into thousands of dollars over the life of a loan. A borrower with strong credit might secure a mortgage a full percentage point lower than someone with weaker credit, saving tens of thousands of dollars across a 30-year term.
It is important to distinguish between the nominal interest rate and the annual percentage rate (APR). The nominal rate is the stated rate before accounting for fees or the effect of compounding within the year. The APR includes certain lender fees and gives a more complete picture of the loan's annual cost, which is why lenders are legally required to disclose it. A related concept, the annual percentage yield (APY), reflects the effect of compounding and is typically used for savings and investments rather than loans.
Compounding refers to how often accrued interest is added to the loan balance so that it, too, begins earning interest. The more frequently a loan compounds, the more interest accrues over time for the same nominal rate. This calculator lets you choose from a range of compounding frequencies - annually, semi-annually, quarterly, monthly, semi-monthly, biweekly, weekly, daily, and even continuously. For most consumer loans in the United States, interest compounds monthly. Mortgages in some countries compound semi-annually. Understanding the compounding frequency of a loan helps you compare offers on an apples-to-apples basis.
Continuous compounding is a theoretical limit in which interest is added an infinite number of times per year. While rarely used in practice for ordinary loans, it is important in finance and is included here for completeness. The difference between monthly and continuous compounding is small for typical rates but grows as the rate increases.
An amortization schedule is a table that lists every payment over the life of an amortized loan and shows how each one is divided between principal and interest, along with the remaining balance after each payment. The schedule reveals a pattern that surprises many first-time borrowers: in the early years, the overwhelming majority of each payment goes toward interest, and only a small slice reduces the principal. This is because interest is charged on the outstanding balance, which is largest at the beginning.
As the loan progresses, the balance falls, the interest portion of each payment shrinks, and the principal portion grows. By the final payments, almost the entire installment goes toward principal. The schedule generated by this calculator lets you view the breakdown payment by payment or summarized year by year, so you can see exactly how your balance declines and how much interest you will have paid at any point in the loan.
Loans fall into two broad categories based on whether they are backed by collateral. A secured loan is tied to an asset - such as a house for a mortgage or a vehicle for an auto loan - that the lender can seize if you default. Because the lender's risk is lower, secured loans typically offer lower interest rates and larger borrowing limits. An unsecured loan, such as most personal loans, credit cards, and student loans, is not backed by collateral. Lenders rely on your creditworthiness alone, so these loans usually carry higher interest rates to compensate for the greater risk.
Knowing which category a loan falls into helps explain its interest rate and terms, and it underscores the stakes of borrowing: defaulting on a secured loan can mean losing the asset, while defaulting on an unsecured loan can severely damage your credit and lead to collections or legal action.
Before taking on any loan, use this calculator to model several scenarios. Compare a 15-year and a 30-year term to see the trade-off between monthly affordability and total interest. Test how much you would save by securing a slightly lower rate, which is often achievable by improving your credit score, making a larger down payment, or shopping multiple lenders. Consider whether making extra payments or paying more frequently fits your budget, since reducing principal early dramatically cuts lifetime interest. Most importantly, make sure the periodic payment fits comfortably within your budget - a common guideline is to keep total debt payments below 36% of your gross income.
An amortized loan is repaid in regular installments throughout the term, with each payment covering both interest and principal so the balance reaches zero by the end. A deferred payment loan requires no payments during the term; instead, interest compounds on the balance and the entire amount is repaid in one lump sum at maturity. Amortized loans spread the cost out, while deferred loans concentrate it at the end and usually cost more in total interest.
The more frequently interest compounds, the more interest accrues for the same nominal rate, because interest is added to the balance more often and then earns interest itself. For typical consumer rates the difference between monthly and daily compounding is modest, but it grows with higher rates and longer terms. This calculator lets you choose the exact compounding frequency so your results match the terms of your specific loan.
Interest is charged on the outstanding balance, which is at its highest at the start of the loan. As a result, the interest portion of each early payment is large and the principal portion is small. As you pay down the balance, the interest charged each period falls and more of your fixed payment goes toward principal. The amortization schedule on this page shows this shift payment by payment.
A shorter term means higher periodic payments but far less total interest, because you are borrowing the money for less time. A longer term lowers each payment, making it more affordable month to month, but you pay more interest overall. The right choice depends on your budget and goals: choose the shortest term whose payment you can comfortably afford to minimize total cost.
A bond promises a fixed face value at maturity. Its price today is that face value discounted back to the present using the interest rate (yield) and compounding frequency. In other words, the calculator finds the amount that, if it grew at the given rate for the term, would equal the face value at maturity. A higher yield or longer term means a lower price today, since the money has more time to grow.
Yes. Paying more frequently - for example, making biweekly payments instead of monthly - reduces the average outstanding balance over time, so less interest accrues. It also often results in the equivalent of one extra monthly payment per year, which shortens the loan and lowers total interest. You can compare payment frequencies directly using the "Pay Back" option on the amortized loan tab.
This Loan Calculator is provided for educational and general informational purposes only. It uses standard amortization and compound-interest formulas and does not account for every fee, tax, insurance cost, or lender-specific rule that may apply to a particular loan. Actual loan terms, payments, and costs may differ. Always review the official terms provided by your lender and consult a qualified financial professional before making borrowing decisions.