Loan Calculator
Estimate monthly, biweekly, or weekly installment payments for personal, auto, and fixed-rate loans. Calculate periodic payment amounts, total interest charges, and loan repayment breakdowns.
Calculate Loan Payment
Enter your loan amount, interest rate, term, and payment frequency.
Estimated Payment Output
Quick Summary
This loan calculator helps borrowers quickly estimate installment payments for personal, auto, and consumer loans across different payment schedules. Enter your loan amount, interest rate, term, and frequency to instantly determine:
- Periodic Payment: The exact payment required per monthly, biweekly, or weekly cycle.
- Total Interest Cost: Cumulative interest charges paid over the complete loan lifecycle.
- Total Payments: The grand sum of all scheduled installments combined.
How to Use the Loan Calculator
- Enter the principal Loan Amount you plan to borrow.
- Enter the annual Interest Rate (APR).
- Enter the Loan Term in years.
- Select your preferred Payment Frequency (Monthly, Biweekly, or Weekly).
- Click Calculate Payment to generate your results.
- Click Reset to restore default inputs and perform another calculation.
Loan Payment Formula
The periodic payment ($M$) for a fixed-rate installment loan is calculated using the standard compound amortization formula:
Where:
- M: Periodic payment amount per cycle
- P: Total principal loan amount
- r: Periodic interest rate ($\text{Annual Rate} \div 100 \div \text{periodsPerYear}$)
- n: Total number of payment periods ($\text{Loan Term in Years} \times \text{periodsPerYear}$)
Zero-Interest Case
If the annual interest rate is 0%, the formula simplifies to linear principal division across payment periods:
Worked Examples
Example 1: $25,000 Loan at 8% Interest for 5 Years (Monthly)
- Loan Amount (P): $25,000
- Monthly Periodic Rate (r): 0.08 ÷ 12 = 0.0066667
- Total Payments (n): 5 À” 12 = 60 payments
Monthly Payment: $506.91 / month
Total Interest Paid: $5,414.59 | Total Payments: $30,414.59
Example 2: $25,000 Loan at 8% Interest for 5 Years (Biweekly)
- Loan Amount (P): $25,000
- Biweekly Periodic Rate (r): 0.08 ÷ 26 = 0.0030769
- Total Payments (n): 5 À” 26 = 130 payments
Biweekly Payment: $233.62 / every 2 weeks
Total Interest Paid: $5,370.38 | Total Payments: $30,370.38
Example 3: $25,000 Loan at 8% Interest for 5 Years (Weekly)
- Loan Amount (P): $25,000
- Weekly Periodic Rate (r): 0.08 ÷ 52 = 0.0015385
- Total Payments (n): 5 À” 52 = 260 payments
Weekly Payment: $116.74 / week
Total Interest Paid: $5,351.42 | Total Payments: $30,351.42
Example 4: $12,000 Zero-Interest Loan for 1 Year (Monthly)
- Loan Amount (P): $12,000
- Interest Rate: 0%
- Total Payments (n): 12 payments
Monthly Payment: $1,000.00 / month
Total Interest Paid: $0.00 | Total Payments: $12,000.00
Understanding Payment Frequencies
Choosing your payment frequency determines how often payments occur and how interest compounds:
- Monthly (12 payments/year): Standard payment schedule occurring once per calendar month.
- Biweekly (26 payments/year): Payments occur every two weeks, resulting in 26 equal payments annually.
- Weekly (52 payments/year): Payments occur every week, resulting in 52 equal payments annually.
Important Note: Biweekly payments are independently calculated based on 26 payment periods per year. Biweekly does not mean simply dividing a monthly payment by two.
What This Calculator Includes vs. Does Not Include
What Is Included
- Principal Repayment: The base loan amount borrowed.
- Fixed Interest Charges: Fixed interest accrued over the loan term.
- Periodic Payment: The exact payment required per monthly, biweekly, or weekly cycle.
- Total Lifetime Costs: Cumulative interest charges and total loan repayments.
What Is Not Included
- Loan Origination Fees: Upfront lender processing fees.
- Late Fees or Penalties: Extra charges for overdue payments.
- Credit Insurance & Taxes: Add-on insurance policies or local sales taxes.
- Prepayment Acceleration: Voluntary extra principal contributions.
Tips for Borrowers
- Evaluate Total Interest Cost: Compare total interest paid across different loan terms rather than focusing solely on monthly payments.
- Consider Shorter Loan Terms: Shorter loan terms feature higher periodic payments but drastically reduce total interest expenses.
- Shop for Lower Interest Rates: Securing even a 1% lower interest rate can save thousands of dollars over a 5-year loan.
Common Mistakes to Avoid
- Assuming Biweekly Means Half Monthly: True biweekly payments are calculated based on 26 periods per year with periodic compounding.
- Ignoring Lender Fees: Always review the lender's loan estimate for origination fees or documentation charges.
- Entering Monthly Rates as APR: Always enter the annual percentage rate (APR); the calculator automatically converts it to the periodic rate.
Frequently Asked Questions (FAQ)
What is a loan calculator?
A loan calculator is a financial tool that computes regular installment payments, total interest, and total repayment costs based on your loan amount, interest rate, term, and frequency.
How is a loan payment calculated?
Fixed-rate loan payments are calculated by applying periodic interest compounding over the total number of payment periods using standard amortization mathematics.
What is the difference between monthly and biweekly payments?
Monthly payments occur 12 times per year. Biweekly payments occur 26 times per year (every two weeks), accelerating principal reduction and reducing lifetime interest.
Does payment frequency affect total interest?
Yes. Higher payment frequencies (biweekly or weekly) reduce the active principal balance more frequently, slightly lowering total interest costs over the loan term.
Can I calculate a 0% interest loan?
Yes. Entering an interest rate of 0% calculates equal principal payments across the total payment periods with $0 total interest.
Does this calculator include loan fees?
No. Origination fees, processing charges, and taxes are excluded. This calculator models pure principal and interest amortization.
Can I use this calculator for a personal loan?
Yes. This calculator accurately models fixed-rate personal loans, unsecured bank loans, and credit union installment loans.
Can I use it for an auto loan?
Yes. It provides an accurate principal and interest estimate for fixed-rate auto loans.
Does the calculator include extra payments?
No. Version 1 models standard scheduled payments without voluntary early prepayments.