Free Loan Calculator – Monthly Payment, Interest & Total Cost
Estimate your monthly loan payment, total interest, payoff date and full amortization schedule in seconds. Built for U.S. personal, auto, student and other fixed-rate installment loans.
- Monthly payment
- Total interest
- Extra payments
- Full schedule
- Download & print
Quick answer: A fixed-rate loan payment depends on three things: the amount you borrow, the annual interest rate and the repayment term. Enter them below to see your estimated monthly payment, total interest and how extra payments can shorten the loan.
Loan Calculator
Fill in the loan details, then select Calculate Loan. Add an optional extra payment to see how much time and interest you could save.
Your estimated loan results
Amortization schedule
| Month | Payment | Principal | Interest | Balance |
|---|
Related Calculators
What Is a Loan Calculator?
A loan calculator estimates what it costs to repay a loan. For a fixed-rate installment loan, you enter the amount borrowed, the annual interest rate and the repayment term. The calculator returns the monthly payment, the total interest you will pay, the total amount repaid and the month-by-month amortization schedule.
Most U.S. personal loans, auto loans and student loans work this way: equal monthly payments over a set term, with each payment covering that month’s interest first and the rest reducing the balance. Mortgages use the same math, but the real monthly housing payment usually adds property taxes, homeowners insurance and sometimes mortgage insurance. For a full housing estimate, use the Mortgage Calculator.
Use a loan calculator before you apply to check affordability, compare offers, choose between a shorter and longer term, or see whether paying extra each month is worth it.
How to Use This Loan Calculator
1. Enter the loan amount
Type the amount you expect to borrow, for example 25000 for a $25,000 loan. If you plan a down payment, enter only the amount you will finance.
2. Enter the annual interest rate
Enter the fixed rate as a percentage. A 7.5% rate is entered as 7.5. Use the interest rate from your offer, not the APR (see the rate vs. APR section).
3. Choose the term
Enter the repayment length and pick years or months. A 5-year loan equals 60 monthly payments.
4. Add an optional extra payment
If you can pay more than the required amount each month, enter it. The calculator shows the shorter payoff time and the interest you could save.
5. Review, save or share the results
After calculating, you can copy the summary, download the schedule as a CSV file, print the results or share them. Use the schedule to see how much of each payment goes to principal and interest.
Loan Payment Formula
For a fixed-rate loan with equal monthly payments, the standard amortization formula is:
M = P × [ r(1 + r)n ] ÷ [ (1 + r)n − 1 ]- M is the monthly payment.
- P is the principal, the amount borrowed.
- r is the monthly interest rate: the annual rate divided by 12, then by 100.
- n is the total number of monthly payments.
For a 0% loan, the formula simplifies to the loan amount divided by the number of payments. The calculator handles this case automatically.
Worked Example: $20,000 at 6% for 5 Years
Here r = 0.06 ÷ 12 = 0.005 and n = 5 × 12 = 60. Plugging these into the formula gives a monthly payment of about $386.66.
Over 60 payments you repay about $23,199.36, which means roughly $3,199.36 goes to interest. The calculator uses the unrounded payment ($386.656…), so its totals can differ by a few cents from a figure multiplied from the rounded payment. Lenders may also round each payment to the cent, which can change the final payment slightly.
Payment examples
| Loan | Rate | Term | Monthly payment | Total interest |
|---|---|---|---|---|
| $10,000 | 8% | 3 years | $313.36 | ≈ $1,281 |
| $20,000 | 6% | 5 years | $386.66 | ≈ $3,199 |
| $30,000 | 7% | 5 years | $594.04 | ≈ $5,642 |
How Amortization Works
Amortization means paying off a loan through scheduled payments that cover both interest and principal. Interest each month is the current balance times the monthly rate, so early payments are mostly interest and later payments are mostly principal.
In the $20,000 example, month 1 interest is $20,000 × 0.005 = $100.00. The remaining $286.66 reduces the balance to about $19,713.34. In month 2, interest falls to about $98.57 and principal rises to about $288.09. This shift continues until the balance reaches zero.
The schedule above shows this for every payment. It is useful for seeing how much interest you have paid at any point, which matters if you plan to refinance or pay the loan off early.
Loan Term Comparison
A longer term lowers the monthly payment but raises total interest. The table compares the same $20,000 loan at 6% over three terms (approximate figures).
| Term | Monthly payment | Total interest |
|---|---|---|
| 3 years (36 payments) | ≈ $608.44 | ≈ $1,904 |
| 5 years (60 payments) | $386.66 | ≈ $3,199 |
| 7 years (84 payments) | ≈ $292.17 | ≈ $4,542 |
Stretching from 3 to 7 years cuts the payment by about $316 a month but adds roughly $2,600 in interest. Pick the shortest term your budget can handle comfortably, and run each option through the calculator before you decide.
How Extra Payments Save Interest
Interest is charged on the remaining balance. When an extra payment goes toward principal, the balance drops sooner, so less interest builds up in every later month.
On the $20,000, 6%, 5-year loan, adding $50 per month brings the payoff from 60 payments to about 53, saving roughly $420 in interest. Enter the same numbers above to check it.
- Ask your lender to apply extra money to principal, not to the next payment’s interest.
- Check the loan agreement for prepayment penalties before paying extra.
- Small, steady extras often help more than waiting for a lump sum.
If you are deciding between paying down a loan and growing savings, compare it with the Compound Interest Calculator.
Personal, Auto, Student and Mortgage Loans
Personal loans
Usually unsecured, with fixed rates and terms from one to several years. Rates depend heavily on credit history, and some lenders charge an origination fee that is not part of the basic payment.
Auto loans
Enter the amount financed after your down payment and trade-in. Sales tax, registration and dealer fees are only included if you add them to the loan amount.
Student loans
Fixed-rate student loans on a standard plan follow the same formula. Income-driven plans, deferment and variable rates need a different calculation.
Mortgages
This tool shows principal and interest only. Taxes, insurance and mortgage insurance raise the real monthly cost, so use the Mortgage Calculator for a home purchase.
For loans that charge simple interest only, try the Simple Interest Calculator.
Interest Rate vs. APR
The interest rate is the cost of borrowing the principal, expressed as a yearly percentage. The annual percentage rate (APR) also reflects certain fees, such as origination charges, so it is usually higher than the rate. Lenders in the U.S. must disclose the APR so you can compare offers.
This calculator needs the interest rate because it models only principal and interest. To compare the full cost of two loans, compare their APRs and the total amount repaid. To see what a percentage change does to a number, use the Percentage Calculator.
How to Lower Your Loan Cost
- Compare offers. Even a one-point difference in rate changes total interest noticeably on larger loans.
- Choose a shorter term if the higher payment fits your budget.
- Make a larger down payment to reduce the amount financed.
- Pay extra toward principal whenever you can.
- Improve your credit profile before applying, since better credit often means a lower rate.
- Watch fees. Origination, late and prepayment fees add to the real cost.
If a lender offers a discount or rate reduction, the Discount Calculator can help you work out the savings, and the Date Duration Calculator shows how long until your final payment date.
Common Loan Calculation Mistakes
- Entering APR as the rate. This overstates the payment slightly because fees get counted as interest.
- Mixing years and months. A 5-year loan is 60 payments, not 5.
- Looking only at the monthly payment. A low payment on a long term can cost far more in interest.
- Forgetting fees and taxes. They are not in the basic payment unless you add them to the amount.
- Treating an estimate as an offer. Only a lender’s disclosure confirms your actual terms.
Calculator Limitations
This tool models a fixed-rate loan with equal monthly payments. It does not cover variable rates, credit cards, lines of credit, interest-only periods, balloon payments, biweekly schedules or lender fees. It treats the rate as compounding monthly, which is how most U.S. installment loans work. Results are estimates for planning, not financial advice or a loan offer. Always confirm figures with your lender’s official payment schedule.
Frequently Asked Questions
How is a monthly loan payment calculated?
The calculator applies the standard amortization formula using the loan amount, monthly interest rate and number of payments to find the equal payment that repays the loan exactly.
How do I calculate total interest on a loan?
Multiply the monthly payment by the number of payments, then subtract the original loan amount. This calculator does it for you and shows the result.
Does a longer term lower my payment?
Yes, spreading the balance over more months lowers the payment, but you pay interest for longer, so total interest is higher.
Can I use this for an auto loan?
Yes. Enter the financed amount, rate and term. Taxes and fees are not included unless you roll them into the amount.
Can I use it for a mortgage?
It estimates principal and interest only. Property taxes, insurance and PMI are extra, so a mortgage-specific calculator gives a fuller picture.
Do extra payments really save money?
Yes, when they are applied to principal. They shorten the loan and cut interest. Check for prepayment penalties first.
What is the difference between interest rate and APR?
The rate is the cost of the borrowed money. APR includes certain fees as well, which makes it better for comparing offers.
Why does my lender’s payment differ slightly?
Lenders may round differently, use exact day counts or add fees and insurance. Small differences are normal.
What is an amortization schedule?
A table showing each payment split into principal and interest, with the remaining balance after every payment.
Is this loan calculator free?
Yes. It is free to use, needs no sign-up and runs in your browser, so your numbers are not stored.
Final Summary
The NINTOZ Loan Calculator estimates the monthly payment, total interest, payoff time and full amortization schedule for a fixed-rate loan. Compare terms, test extra payments, then download, print or share your results. Before signing, confirm the numbers against your lender’s official disclosures.