Loan Calculator – Calculate Loan Payments, Interest & Amortization Schedules

Loan Calculator – Calculate Loan Payments, Interest & Amortization Schedules

  • Adam
  • November 2, 2025

Free loan calculator for mortgages, auto loans, and personal loans. Calculate monthly payments, total interest, and generate amortization schedules. Supports amortized loans, deferred payment loans, and bonds.

💰 Loan Calculator

Calculate Loan Payments, Interest & Amortization

A loan is a contract between a borrower and a lender in which the borrower receives an amount of money (principal) that they are obligated to pay back in the future. Most loans can be categorized into one of three categories:

  • Amortized Loan: Fixed payments paid periodically until loan maturity
  • Deferred Payment Loan: Single lump sum paid at loan maturity
  • Bond: Predetermined lump sum paid at loan maturity (the face or par value of a bond)

💡 Tip: Use this calculator for basic calculations of common loan types such as mortgages, auto loans, student loans, or personal loans, or click the links for more detail on each.

Use this calculator for basic calculations of common loan types such as mortgages, auto loans, student loans, or personal loans, or click the links for more detail on each.

💻 Loan Details

$
years
Additional months
%

✅ Results

Payment Every Month
$0
Total of Payments
$0
Total Interest
$0
Principal vs Interest Breakdown
Principal: 0%
Interest: 0%
📋 View Amortization Table

Use this calculator to compute how much you will owe at the end of the loan period by making no payments until the maturity date.

💻 Loan Details

$
years
Additional months
%

✅ Results

Amount Due at Loan Maturity
$0
Total Interest
$0
Principal vs Interest Breakdown
Principal: 0%
Interest: 0%
📋 View Schedule Table

Use this calculator to compute the initial value of a bond/loan based on a predetermined face value to be paid back at bond/loan maturity.

💻 Loan Details

$
years
Additional months
%

✅ Results

Amount Received When the Loan Starts
$0
Total Interest
$0
Principal vs Interest Breakdown
Principal: 0%
Interest: 0%

📘 What is a Loan Calculator?

A Loan Calculator is a comprehensive financial tool designed to help borrowers and lenders understand the financial implications of different loan types. This calculator specifically handles three main categories of loans: amortized loans (where you make fixed periodic payments), deferred payment loans (where you pay a lump sum at maturity), and bonds (which have a predetermined face value). By inputting key loan parameters such as the principal amount, interest rate, loan term, and compounding frequency, the calculator automatically computes payment schedules, total interest paid, and other critical loan metrics.

Whether you're considering a mortgage, auto loan, student loan, or personal loan, this calculator provides essential insights into your borrowing costs and helps you make informed financial decisions. The calculator supports multiple compounding frequencies and payment schedules, making it adaptable to various real-world lending scenarios.

🔢 Formulas & Methodology

Amortized Loan Calculations

An amortized loan involves making fixed periodic payments until the loan is fully repaid. The monthly payment is calculated using the standard amortization formula:

Monthly Payment Formula
M = P × [ r(1+r)^n ] / [ (1+r)^n - 1 ]

Where:

  • M = Monthly payment amount
  • P = Principal loan amount
  • r = Monthly interest rate (annual rate ÷ 12 ÷ 100)
  • n = Total number of payments
Total Interest Calculation
Total Interest = (M × n) - P

The total interest is the difference between all payments made and the original principal.

Remaining Balance After k Payments
B_k = P × [ (1+r)^n - (1+r)^k ] / [ (1+r)^n - 1 ]

This formula shows how much principal remains after making k payments.

Deferred Payment Loan Calculations

A deferred payment loan involves no periodic payments; instead, the entire amount (principal plus accumulated interest) is paid at maturity:

Amount Due at Maturity
A = P × (1 + r/n)^(n×t)

Where:

  • A = Amount due at maturity
  • P = Principal loan amount
  • r = Annual interest rate (as a decimal)
  • n = Compounding frequency per year (1 for annual, 2 for semi-annual, 4 for quarterly, 12 for monthly)
  • t = Time in years
Total Interest for Deferred Loan
Total Interest = A - P

Bond Calculations

A bond has a predetermined face value (maturity value) that will be paid at maturity. The initial loan amount (present value) is calculated by discounting the face value:

Present Value of Bond
PV = FV / (1 + r/n)^(n×t)

Where:

  • PV = Present value (initial loan amount)
  • FV = Face value (predetermined due amount)
  • r = Annual interest rate (as a decimal)
  • n = Compounding frequency per year
  • t = Time in years
Bond Discount/Premium
Total Interest = FV - PV

This represents the total discount (or premium if negative).

📖 How to Use This Loan Calculator

Step-by-Step Guide for Amortized Loans

Step 1: Select the Loan Type

Click on the "Amortized Loan" tab at the top if it's not already selected. This is the most common loan type for mortgages, auto loans, and personal loans.

Step 2: Enter the Loan Amount

Input the total principal amount you're borrowing (e.g., $100,000 for a mortgage or $25,000 for a car loan).

Step 3: Specify the Loan Term

Enter the loan term in years and months. For example, a 30-year mortgage would be "30 years" and "0 months". A 5-year car loan with an additional 3 months would be "5 years" and "3 months".

Step 4: Enter the Interest Rate

Input the annual percentage rate (APR). This is typically found in your loan offer documents. For example, a typical mortgage rate might be 6%, while credit card rates could be 20%+.

Step 5: Select Compounding Frequency

Choose how often interest is compounded (Monthly, Quarterly, Semi-Annual, or Annually). Most consumer loans compound monthly (APR - Annual Percentage Rate).

Step 6: Choose Payment Frequency

Select how often you make payments (Monthly, Quarterly, Semi-Annual, or Annually). Most borrowers pay monthly.

Step 7: Click Calculate

Press the green "Calculate" button to see your results, including monthly payment, total payments, and total interest.

Step 8: Review the Results

See your monthly payment, total amount you'll pay, total interest, and a visual breakdown of principal vs interest. Click "View Amortization Table" to see a detailed month-by-month payment schedule.

Using Deferred Payment & Bond Calculators

The process is similar for deferred payment loans and bonds. Simply enter the loan amount (or face value for bonds), term, interest rate, and compounding frequency. The calculator will show you how much you'll owe at maturity.

❓ Frequently Asked Questions

What is the difference between APR and APY? ▼
APR (Annual Percentage Rate) is the nominal annual interest rate without accounting for compounding. APY (Annual Percentage Yield) accounts for compounding and represents the true annual rate of return. APY is always higher than APR when compounding occurs more frequently than annually. For loans, APR is more commonly used.
What is an amortization table? ▼
An amortization table is a detailed breakdown of each loan payment showing how much goes toward principal and how much goes toward interest. It tracks the remaining balance after each payment. This helps borrowers understand how their loan is being paid down over time and plan their finances accordingly.
How do I reduce the total interest paid on my loan? ▼
There are several strategies to reduce total interest: (1) Make a larger down payment - reduces the loan principal, (2) Choose a shorter loan term - results in higher monthly payments but less total interest, (3) Make extra payments - paying more than the minimum amount applies directly to principal, (4) Refinance to a lower rate - if rates drop, you can refinance at better terms. Any of these approaches will significantly reduce total interest paid.
What is the difference between fixed and variable interest rates? ▼
Fixed-rate loans have the same interest rate throughout the life of the loan, making payments predictable. Variable-rate loans have interest rates that change periodically based on market conditions. Fixed rates are generally safer as your payment never changes, while variable rates might start lower but could increase significantly. This calculator assumes fixed rates.
Can I use this calculator for credit card debt? ▼
Yes! You can use the amortized loan calculator to see how long it would take to pay off a credit card balance if you made fixed monthly payments. Credit card APRs are typically much higher (15-25%) compared to other loans. This calculator helps you understand the impact of different payment amounts on your payoff timeline and total interest.
What is a balloon payment? ▼
A balloon payment is a large lump-sum payment due at the end of the loan term. Some car loans and mortgages use this structure, where you make regular monthly payments but then owe a large amount at the end. This isn't specifically calculated by this tool, but it combines elements of amortized and deferred payment loans.
How does extra payment reduce my loan term? ▼
When you pay more than your minimum monthly payment, the extra amount goes directly toward reducing the principal. Since interest is calculated on the remaining principal, paying down principal faster means less interest accumulates over time, and the loan is paid off sooner. For example, paying $50 extra monthly on a 30-year mortgage could reduce the loan term by several years.
What is loan refinancing? ▼
Refinancing means taking out a new loan to pay off an existing loan, usually at better terms. People refinance when interest rates drop, to change the loan term, to consolidate multiple loans, or to switch from variable to fixed rates. While refinancing has upfront costs, the savings from a lower interest rate often outweigh these costs over time.
How is loan interest calculated daily? ▼
Many loans calculate interest on a daily basis using the formula: Daily Interest = (Principal × Annual Rate) / 365. This means your daily balance affects how much interest accrues each day. Some loans use a 360-day year for calculations. This calculator uses the standard compounding methods (monthly, quarterly, etc.) rather than daily calculations for simplicity.
Why is my monthly payment higher/lower than expected? ▼
Your monthly payment depends on four factors: loan amount, interest rate, loan term, and compounding frequency. A higher interest rate, shorter loan term, or larger loan amount will result in higher monthly payments. If your calculated payment doesn't match your actual loan statement, double-check your interest rate (check for APR vs APY) and ensure you've entered the correct loan term in years and months.

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