Amortization Calculator

Create detailed loan amortization schedules with monthly and yearly views. Calculate total interest, add extra payments, and see how to pay off loans faster.

Loan Details

Years

Months

Results

Enter your loan details and click Calculate to see results

Understanding Loan Amortization

What is Amortization?

Amortization is the process of paying off a debt (such as a loan or mortgage) through regular, scheduled payments over a specific period. Each payment consists of two components:

  • Principal: The portion that reduces the outstanding loan balance
  • Interest: The cost of borrowing the money, calculated on the remaining balance

An amortization schedule is a detailed table showing every payment throughout the life of the loan, breaking down exactly how much of each payment goes toward principal versus interest.

Amortization Formula

The monthly payment for an amortized loan is calculated using the following formula:

Monthly Payment Formula:
M = P × r(1 + r)n / (1 + r)n − 1
M = Monthly payment
P = Principal loan amount
r = Monthly interest rate (annual rate ÷ 12)
n = Total number of payments (years × 12)

How Interest is Calculated Each Month

For each payment period, the interest and principal portions are calculated as follows:

Monthly Interest Payment:
Interest = Remaining Balance × Monthly Interest Rate
Monthly Principal Payment:
Principal = Monthly Payment − Interest
New Balance:
New Balance = Previous Balance − Principal

Example Calculation

Let's calculate the amortization for a $200,000 loan at 6.5% annual interest for 30 years:

Given:
  • Principal (P) = $200,000
  • Annual Interest Rate = 6.5%
  • Loan Term = 30 years = 360 months
Calculate Monthly Payment:
  • Monthly rate (r) = 6.5% ÷ 12 = 0.065 ÷ 12 = 0.00542
  • Number of payments (n) = 30 × 12 = 360
Solution:
M = 200,000 × [0.00542(1.00542)360] / [(1.00542)360 − 1]
M = 200,000 × 0.00632 / 1.166
M = $1,264.14

First Few Months Breakdown:

MonthPaymentPrincipalInterestBalance
1$1,264.14$180.81$1,083.33$199,819.19
2$1,264.14$181.79$1,082.35$199,637.40
3$1,264.14$182.78$1,081.36$199,454.62

Notice how the interest portion starts high ($1,083.33) and the principal portion starts low ($180.81). Over time, these proportions reverse as the balance decreases.

Types of Amortized Loans

1. Mortgages (Home Loans)

Home mortgages are typically amortized over 15 or 30 years. A 30-year mortgage has lower monthly payments but costs significantly more in total interest. A 15-year mortgage has higher monthly payments but saves substantial interest over the life of the loan.

2. Auto Loans

Car loans are usually amortized over 3-7 years. Shorter terms mean higher monthly payments but less total interest paid. Auto loans typically have lower interest rates than personal loans because the vehicle serves as collateral.

3. Personal Loans

Personal loans are commonly amortized over 2-5 years. These unsecured loans typically have higher interest rates than secured loans. The fixed payment schedule makes budgeting easier compared to revolving credit like credit cards.

4. Student Loans

Student loans are often amortized over 10-25 years. Federal student loans offer standard 10-year repayment plans, but extended and income-driven plans can stretch to 20-25 years. Longer terms reduce monthly payments but increase total interest significantly.

Benefits of Extra Payments

Making extra payments toward your loan principal can result in substantial savings:

Example: Impact of $200 Extra Monthly Payment

Consider a $200,000 loan at 6.5% for 30 years (monthly payment = $1,264.14):

ScenarioPayoff TimeTotal InterestSavings
No extra payment30 years$255,088
$200 extra/month21.5 years$178,468$76,620

Result: Save $76,620 in interest and pay off 8.5 years earlier!

Amortization vs. Other Payment Methods

TypePayment StructureExamples
Amortized LoanFixed payments, principal increases over time, interest decreasesMortgages, auto loans, personal loans
Interest-Only LoanPay only interest initially, principal due later or in balloon paymentSome mortgages, business loans
Revolving CreditVariable payments based on balance, can borrow repeatedly up to limitCredit cards, lines of credit
Balloon LoanSmall regular payments with large final paymentSome commercial real estate loans

Reading an Amortization Schedule

An amortization schedule typically includes the following columns:

  • Payment Number/Date: Sequential payment identifier or date
  • Payment Amount: Total payment due (usually fixed)
  • Principal: Amount reducing the loan balance
  • Interest: Cost of borrowing for that period
  • Remaining Balance: Loan amount still owed after payment
  • Cumulative Interest: Total interest paid to date

Strategies to Pay Off Loans Faster

1. Round Up Payments

Round your monthly payment to the nearest $50 or $100. For example, if your payment is $1,264, pay $1,300. This small increase adds up significantly over the loan term.

2. Make Bi-weekly Payments

Pay half your monthly payment every two weeks. This results in 26 half-payments (13 full payments) per year instead of 12, effectively making one extra payment annually.

3. Apply Windfalls to Principal

Use bonuses, tax refunds, or other unexpected income to make lump-sum principal payments. Always specify these are principal-only payments to ensure they reduce your balance.

4. Refinance to Shorter Term

If you can afford higher payments, refinance from a 30-year to a 15-year loan. You'll typically get a lower interest rate and save dramatically on total interest paid.

Frequently Asked Questions

1. What is negative amortization?

Negative amortization occurs when your monthly payment doesn't cover the interest due, causing the unpaid interest to be added to the principal balance. This increases your loan balance over time instead of decreasing it. This can happen with certain adjustable-rate mortgages or payment-option loans.

2. How is amortization different from depreciation?

Amortization applies to paying off debts or allocating the cost of intangible assets (like patents) over time. Depreciation applies to allocating the cost of tangible assets (like equipment or vehicles) over their useful life. Both are accounting methods to spread costs over time.

3. Do all loans have amortization schedules?

No. Only installment loans with fixed payments have traditional amortization schedules. Credit cards, lines of credit, and interest-only loans don't follow standard amortization. Balloon loans have modified amortization with a large final payment.

4. Can I get a copy of my loan's amortization schedule?

Yes. Your lender should provide an amortization schedule when you close on the loan. You can also request one at any time or use an amortization calculator with your loan terms to generate one yourself. The schedule may change if you make extra payments or refinance.

5. Will extra payments always reduce my loan term?

Extra payments reduce the principal balance, which reduces future interest charges. However, you must specify that extra payments go toward principal, not future payments. Some lenders may apply extra payments to future scheduled payments instead, which doesn't reduce your loan term or save interest. Always confirm with your lender.

6. What is an amortization period vs. loan term?

The amortization period is the time it would take to fully pay off the loan through regular payments. The loan term is the actual length of the loan contract. In some cases (like balloon loans), these differ—the loan may be amortized over 30 years but have a 5-year term requiring refinancing or a balloon payment.

7. How do prepayment penalties work?

Some loans charge a fee if you pay off the loan early or make extra payments beyond a certain limit. Prepayment penalties protect lenders from losing expected interest income. Always check your loan agreement for prepayment terms. Many mortgages no longer have these penalties, but some commercial and auto loans do.

8. What happens if I miss a payment?

Missing a payment doesn't change your amortization schedule—it adds late fees and damages your credit score. The unpaid payment accrues additional interest. After 30 days, it's reported to credit bureaus. Multiple missed payments can lead to default and foreclosure (for secured loans) or collections (for unsecured loans).

9. Should I pay off my loan early or invest the money?

This depends on your loan's interest rate versus potential investment returns. If your loan has a high interest rate (above 6-7%), paying it off early often makes sense. If your loan has a low rate (below 4%), investing may yield better returns. Consider your risk tolerance, emergency fund needs, and tax implications (mortgage interest is sometimes tax-deductible).

10. How does refinancing affect my amortization?

Refinancing creates a new loan with a new amortization schedule. Even if you refinance the same balance for the same term, the "clock resets"—you start over with high-interest, low-principal payments. This is why refinancing to a shorter term (e.g., 30-year to 15-year) or refinancing for a lower rate makes more financial sense than repeatedly refinancing to 30 years.

Need Help with Loan Calculations?

Our expert tutors can help you understand amortization, financial mathematics, and loan analysis. Book a personalized session today!