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Additional Payment Calculator

See how extra payments reduce your loan term and total interest. Perfect for paying off loans faster.

Monthly Payment
$536.82
Total Payments
360
Total Interest
$93255.78
Total Payment
$193255.78

Remaining Balance Over Time

  • Remaining Balance

Principal vs Interest

  • Principal
  • Interest

Additional payment calculator

Formula

Original loan monthly payment:

M=Ptimesfracr(1+r)n(1+r)n−1M = P \\times \\frac{r(1+r)^n}{(1+r)^n - 1}

With additional payment, the loan balance decreases faster. The new payoff time is found by solving:

Bt=P(1+r)t−Mfrac(1+r)t−1r−Afrac(1+r)t−1rB_t = P(1+r)^t - M\\frac{(1+r)^t - 1}{r} - A\\frac{(1+r)^t - 1}{r}

Where A is the additional monthly payment.

Worked example

$200,000 loan at 5% over 30 years:

  1. Original monthly payment: $1,073.64
  2. Total interest: $186,511
  3. Original term: 360 months

Add $200 extra per month:

  1. New payment: $1,273.64
  2. New term: approximately 246 months (20.5 years)
  3. Total interest: $121,651
  4. Savings: $64,860 in interest, 114 months (9.5 years)

How to use

  1. Enter the loan amount
  2. Enter the interest rate
  3. Enter the original term
  4. Enter the additional monthly payment
  5. Click "Calculate"

Payment allocation

Each monthly payment goes to:

  1. Interest for the month: Remaining balance × monthly rate
  2. Principal: Payment - interest
  3. Additional payment: Directly reduces principal

The additional payment immediately reduces future interest calculations.

Extra payment strategies

  • Monthly extra: Small, consistent additions
  • Lump sum: One-time large payment
  • Bi-weekly: Pay half every two weeks = 13 payments per year
  • Year-end extra: Additional payment each December

Common use cases

  • Early mortgage payoff
  • Credit card debt reduction
  • Auto loan payoff
  • Student loan management
  • Debt-free planning

FAQ

Does extra payment go to principal? Yes, specify "apply to principal" when making the payment.

Can I make extra payments anytime? Check your loan terms. Some have prepayment penalties.

How much extra should I pay? Even $50-100 per month makes a significant difference.

What about lump sums? One large payment can reduce the term substantially, especially early in the loan.

Does this work for all loans? Yes, but check for prepayment penalties first.

Should I invest instead? Compare the loan interest rate to your expected investment return. Higher loan rates favor paying down debt.

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