Loan Calculator
Use this loan calculator to estimate how a fixed-rate installment loan could cost each month, how much you may pay over the full term, and how much of that total may go toward interest.
It is built as a broad borrowing-planning tool for comparing how loan amount, interest rate, and loan term change monthly payment, total paid, and total interest across many fixed-term borrowing scenarios.
You can enter the term in years or months, which makes it easier to model common repayment lengths such as 36, 48, 60, 72, and 84 months.
If you are specifically planning around unsecured borrowing for debt consolidation, emergency expenses, or home repairs, compare it with the Personal Loan Calculator.
If you want to work backward from a monthly payment budget to an estimated borrowing amount, use the Loan Affordability Calculator.
Know the loan amount, payment, and term but not the rate? Use the Loan Interest Rate Calculator.
If you are financing a car and need to model trade-in value, sales tax, and dealer fees, use the Auto Loan Calculator.
If you are planning a home purchase with taxes, insurance, HOA, or PMI, use the Mortgage Calculator instead.
Results are planning estimates only. Fees, APR differences, and lender-specific terms may not be included, and actual loan offers can vary.
How to use this calculator
- Enter the amount you plan to borrow.
- Add the fixed interest rate you want to model.
- Choose years or months and enter the repayment term. Use the quick-select chips (36, 48, 60, 72, 84 months) to compare common terms.
- Optionally enter an extra monthly payment to see how additional principal payments affect payoff date, total interest, and time saved.
- Set the loan start month to calculate the estimated payoff date.
- Review the estimated monthly payment, payoff date, total paid, total interest, and the principal vs. interest breakdown.
The comparison table shows how the same loan amount and rate play out across five standard terms without extra monthly payments, so you can weigh monthly affordability against total cost. Click "View full amortization schedule" for a month-by-month payment breakdown.
How it works
This calculator estimates your monthly payment using the loan amount, interest rate, and repayment term.
It is designed as a general fixed-rate installment loan estimator for comparing how amount, rate, and term affect cost over time. An optional extra monthly payment models additional principal payments using a month-by-month schedule.
Monthly payment formula
M = P × r × (1 + r)n / ((1 + r)n − 1)
Main inputs in the estimate
- M
- Estimated monthly payment
- P
- Loan amount (principal)
- r
- Monthly rate derived from annual rate (annual rate ÷ 12 ÷ 100)
- n
- Total number of monthly payments over the repayment term
What the estimate assumes
- The estimate assumes a fixed interest rate and equal monthly payments over the full term.
- Total paid and total interest are the sum of per-month amounts from the amortization schedule. The monthly payment displayed is rounded to the nearest cent, so multiplying it by the number of payments may differ from total paid by a few cents.
- When an extra monthly payment is entered, each month's extra amount is applied to principal after interest. The final payment is capped at the remaining balance, so the actual last payment may be smaller.
- Fees, APR differences, lender-specific rules, and official payoff quotes are not included.
Assumptions and limitations
- Results are estimates based on a fixed interest rate over the full repayment term.
- Total paid and total interest are the sum of per-month amounts from the amortization schedule. The displayed monthly payment is rounded to the nearest cent, so multiplying it by the number of payments may differ from total paid by a few cents.
- Loan term can be entered in years or months for broader installment-loan planning.
- Optional extra monthly payments are applied entirely to principal after that month's interest. The final payoff payment may be smaller because it is capped at the remaining balance plus that month's interest, and the payoff date is an estimate.
- Fees, APR differences, lender-specific charges, and official lender payoff quotes are not included.
- This calculator is for planning only and is not a formal loan quote or approval.
What this loan calculator can estimate
Use this page when you already have a loan amount in mind and want to compare fixed-rate installment loan costs before borrowing. It can estimate:
- Monthly payment based on the loan amount, fixed interest rate, and repayment term.
- Total interest paid over the repayment schedule.
- Total paid, also called the full loan cost before lender fees or other charges.
- Payoff timing when you add extra monthly principal payments.
If you are trying to work backward from a monthly payment budget to an estimated borrowing amount, use the Loan Affordability Calculator. For a broader overview of payment math, loan terms, and borrowing decisions, start with Loan Basics.
Installment loan payment calculator
Use this installment loan calculator for fixed-rate loans with equal monthly payments. Enter the amount borrowed, interest rate, and repayment term to compare your monthly payment, total interest, and full loan cost.
For loan-type-specific assumptions, use the dedicated calculators. The Personal Loan Calculator is better for unsecured personal-loan scenarios, the Auto Loan Calculator adds vehicle-specific inputs such as down payment, trade-in value, taxes, and fees, and the Mortgage Calculator is built for home-loan inputs such as taxes, insurance, HOA, and PMI. If you want the month-by-month balance breakdown, open the Amortization Calculator.
How to calculate total interest on a loan
Total interest = total paid - loan amount
For a standard fixed-rate installment loan, total paid is the sum of all scheduled payments over the repayment term. The difference between that total and the original loan amount is the estimated interest cost.
Extra monthly payments can reduce total interest because they lower the principal balance faster. In this calculator, extra payments are modeled as additional principal payments after each month's interest, which can shorten the payoff timeline and reduce the total paid. When the loan pays off early, the final payment may be smaller than the regular payment because it is capped at the remaining balance plus that month's interest.
Example scenario
Use this example to see how a neutral fixed-rate installment loan estimate can help you compare the effect of amount, rate, and term.
- Loan amount:
$20,000 - Interest rate:
8.5% - Loan term:
5 years (60 months) - Extra monthly payment:
$0
With those inputs, the estimated monthly payment is $410.33.
The estimated total paid over the loan term is $24,619.84.
That means total interest paid is about $4,619.84.
Now add a $100 extra monthly payment starting in May 2026. The effective payment becomes $510.33, but the final payoff payment may be smaller because it is capped at the remaining balance. The loan pays off in roughly 47 payments, with an estimated payoff date of Mar 2030. Total interest drops to about $3,510.64, saving about $1,109.19 in interest and finishing about 13 months earlier.
This example shows why a general loan calculator is useful for comparison: monthly affordability, long-term borrowing cost, and the impact of extra payments can all change meaningfully with different inputs.
Frequently asked questions
What is a loan calculator used for?
A loan calculator helps you estimate monthly payment, total paid, and total interest for a fixed-rate loan before you apply with a lender.
Can I enter the loan term in months?
Yes. You can switch between years and months, which is useful for modeling common repayment lengths such as 36, 48, 60, 72, and 84 months.
How does loan term affect monthly payment and total interest?
A longer term usually lowers the monthly payment because you spread repayment over more months, but it often increases total interest. A shorter term usually raises the monthly payment while reducing total interest.
Does this calculator show monthly payments?
Yes. The main result is an estimated monthly payment based on the loan amount, interest rate, and repayment term you enter.
Does it include fees or APR?
No. This version focuses on the base fixed-rate payment estimate. Origination fees, APR differences, and lender-specific charges are not included. Use the interest rate field only.
What does the extra monthly payment field do?
When you enter an amount greater than zero, the calculator models additional principal payments applied each month after that month's interest. It estimates the new payoff date, total interest paid with extra payments, interest saved, and months saved compared to the standard schedule. The payoff date is an estimate and actual results may vary by one payment.
How do fixed-rate installment loans work?
A fixed-rate installment loan is typically repaid with equal monthly payments over a set term. Each payment usually covers both principal and interest, and the payment amount stays the same if the rate does not change.
What is the difference between APR and interest rate?
Interest rate is the base borrowing rate used to calculate the payment. APR can include interest plus certain fees, so it may be higher than the interest rate. This calculator uses the interest rate you enter and does not calculate APR.
What affects my monthly loan payment?
The biggest drivers are the amount borrowed, the interest rate, and the repayment term. Larger loans and higher rates usually raise the payment, while longer terms can lower the monthly payment but increase total interest.
How can I lower my monthly payment?
Common ways include borrowing less, qualifying for a lower rate, or choosing a longer repayment term. A longer term can reduce the monthly payment but often increases the total interest paid.
Why is the total paid higher than the amount borrowed?
Because interest adds borrowing cost over time. The longer the term and the higher the interest rate, the larger the total paid can become.
Is this a lender quote?
No. This is a planning estimate, not a lender quote or loan approval. Actual offers vary by credit profile, fees, lender terms, and underwriting.
Can I use this for personal or auto loans?
Yes. It works well for general fixed-rate installment loan planning, including many personal loans and auto loans. If you want a vehicle-specific estimate that includes down payment, trade-in value, taxes, and fees, use the Auto Loan Calculator.
Related Calculators
Loan Interest Rate Calculator
Estimate a fixed loan interest rate from the loan amount, equal monthly payment, and repayment term.
Loan Affordability Calculator
Estimate the maximum fixed-rate loan amount that may fit a monthly payment budget, APR, and repayment term.
Amortization Calculator
View a full amortization schedule for a fixed-rate loan, including principal, interest, remaining balance, payoff timing, and the impact of extra monthly payments.
Personal Loan Calculator
Estimate your fixed personal loan payment, amortization schedule, total paid, and total interest, with optional extra monthly payments.