Loan Calculator
Loan Calculator User Manual
Table of Contents
- Introduction
- Getting Started
- Input Fields
- Calculations
- Amortization Schedule
- Tips & Best Practices
- Frequently Asked Questions
Introduction
This Loan Calculator helps you understand your loan repayment details by calculating:
- Monthly payment amount
- Total interest paid over the loan term
- Complete amortization schedule (payment-by-payment breakdown)
The calculator is designed to work on all devices (computers, tablets, and smartphones) and requires no installation.
Getting Started
- Open the Loan Calculator in your web browser
- Enter your loan details in the input fields
- Click “Calculate Payment” to see results
- Use “Reset” to clear all fields and start over
Input Fields
Loan Amount
- Enter the total amount you’re borrowing
- Example: For a $250,000 mortgage, enter “250000”
Interest Rate
- Enter the annual interest rate for your loan
- Example: For 3.5% interest, enter “3.5”
- Note: This should be the nominal rate (not APR)
Loan Term
- Enter the duration of your loan
- Combine with Term Type (below) to specify years or months
- Example: For a 30-year loan, enter “30” and select “Years”
Term Type
- Choose whether your loan term is in “Years” or “Months”
- Most mortgages and auto loans use years
- Short-term loans often use months
Calculations
After clicking “Calculate Payment”, you’ll see three key results:
- Monthly Payment
- The fixed amount you’ll pay each month
- Includes both principal and interest
- Total Interest
- The total amount of interest you’ll pay over the loan term
- Shows the true cost of borrowing
- Total Payment
- The sum of all payments (principal + interest)
- Equals loan amount plus total interest
Amortization Schedule
The detailed payment-by-payment breakdown shows:
- Period: Payment number (month)
- Payment: Monthly payment amount
- Principal: Portion going toward loan balance
- Interest: Portion going toward interest charges
- Remaining: Outstanding balance after payment
Using the Amortization Schedule
- Click “Show Amortization Schedule” to view the complete breakdown
- The schedule highlights every 12th payment (annual summary)
- Includes a totals row at the bottom
- On mobile devices, scroll horizontally to see all columns
Tips & Best Practices
- Compare Loan Options
- Try different interest rates to see how they affect total cost
- Compare 15-year vs. 30-year mortgages
- Extra Payments
- To model extra payments, reduce the principal amount accordingly
- Example: For $100 extra each month, subtract (100 × term) from loan amount
- Refinancing Analysis
- Compare current loan with potential new loan terms
- Consider closing costs by adding them to the loan amount
- Printing Results
- Use your browser’s print function (Ctrl+P or Cmd+P)
- Select “Save as PDF” to keep a digital copy
Frequently Asked Questions
Q: Why doesn’t my payment match the bank’s quote?
A: This calculator doesn’t include taxes, insurance, or fees that may be part of your actual payment.
Q: How do I calculate a bi-weekly payment?
A: Enter half your monthly amount and select “Months” for term, then double the number of months.
Q: Can I calculate adjustable rate loans?
A: This calculator assumes a fixed rate. For ARMs, calculate each fixed-rate period separately.
Q: The numbers seem slightly off – why?
A: Due to rounding in actual payments, there may be small differences (usually < $1).
Q: How do I account for a balloon payment?
A: Reduce the loan term to the balloon period and the loan amount to the financed portion.