Why do early loan payments go mostly toward interest?

Interest is charged on the remaining balance each period, and at the start of the loan the balance is at its largest. On a $300,000 loan at 6.5%, the first monthly payment of $1,896 includes $1,625 of interest and only $271 of principal. As the balance falls, the interest portion shrinks and more of each level payment goes to principal — the schedule flips to mostly principal in the later years.

How much can extra payments save on a mortgage?

Extra payments apply directly to principal, so they eliminate the interest that balance would have accrued over every remaining period. On a $300,000, 30-year loan at 6.5%, an extra $200 per month saves roughly $100,000 in interest and pays the loan off about 7 years early. The earlier in the loan you make extra payments, the more interest each dollar saves.

What is the difference between bi-weekly and accelerated bi-weekly payments?

True bi-weekly payments split the loan into 26 smaller payments per year sized to follow the same payoff schedule as monthly payments. Accelerated bi-weekly payments take half the monthly payment and pay it 26 times a year — the equivalent of 13 full monthly payments annually — which pays the loan off years earlier and saves significant interest.

How does a balloon loan differ from a fully amortizing loan?

A fully amortizing loan reaches a zero balance at the end of its term. A balloon loan uses a lower periodic payment that does not fully retire the principal, leaving a large lump sum — the balloon — due at maturity. The amortization period (used to size the payment) is longer than the actual loan term, so borrowers must plan to refinance, sell, or pay the balloon when it comes due.

Amortization Calculator

Generate detailed amortization schedules showing principal and interest breakdown over time. Free, accurate, no signup.

Loan Details

Loan Amount & Terms

Loan Amount

Total amount of the loan

Interest Rate (Annual)

Annual interest rate

Loan Term

Length of the loan

Term Unit

Payment Options

Payment Frequency

Payment Type

Extra Payment

Additional payment per period

Start Date

Amortization Analysis

Monthly Payment

$1,896

Scheduled payment per period

Total Interest

$382,633

Over life of loan

Total Payments

360

Number of payments

Principal vs Interest

Balance Over Time

Remaining principal after each scheduled payment.

Total Paid

$682,633

Principal + Interest

Payoff Date

5/13/2056

Final payment date

Payment Breakdown

Principal Amount:$300,000

Total Interest:$382,633

Total Amount:$682,633

Amortization Tips

• Early payments go mostly toward interest, later payments toward principal
• Extra principal payments can significantly reduce total interest
• True bi-weekly payments follow roughly the same payoff schedule as monthly — choose Accelerated Bi-weekly (half the monthly payment, 26 times a year) to make the equivalent of 13 monthly payments and pay off years early
• Consider refinancing if interest rates have dropped significantly

How it works

An amortization schedule breaks a fixed payment down, period by period, into interest and principal. Each period the lender charges interest on the current balance; the rest of your level payment reduces the principal. As the balance falls, the interest portion shrinks and the principal portion grows — which is why a schedule starts interest-heavy and ends principal-heavy.

Splitting each payment

Interestₖ = Balanceₖ₋₁ · r        Principalₖ = M − Interestₖ        Balanceₖ = Balanceₖ₋₁ − Principalₖ

M: the fixed payment = P · r(1+r)ⁿ / [(1+r)ⁿ − 1]
r: periodic interest rate
Balanceₖ: remaining principal after payment k

Worked example

$200,000 loan at 6% → r = 0.5%/month, payment M ≈ $1,199
First payment, balance = $200,000

Interest = 200,000 × 0.005 = $1,000
Principal = 1,199 − 1,000 = $199

Payment 1 is $1,000 interest / $199 principal; by the final payment it's almost entirely principal.

Good to know

Extra payments apply directly to principal, so they skip the interest on every remaining period — the earlier you make them, the more they save.
Interest-only or balloon loans don't amortize fully: the balance doesn't reach zero on schedule, leaving a lump sum due at the end.
The "halfway point" in time is not the halfway point in equity — on a 30-year loan you don't cross 50% paid-off until ~year 19.