Loan Forgiveness Calculator Formula

Understand the math behind the loan forgiveness calculator. Each variable explained with a worked example.

Formulas Used

Estimated Amount Forgiven

forgiven_amount = original_balance * pow(1 + monthly_rate, payments_made) - monthly_payment * (pow(1 + monthly_rate, payments_made) - 1) / monthly_rate

Total Amount Paid

total_paid_out = total_paid

Qualifying Payments Remaining

payments_remaining = max(0, 120 - payments_made)

Variables

VariableDescriptionDefault
original_balanceOriginal Loan Balance ($)60000
annual_rateAnnual Interest Rate (%)6
monthly_paymentMonthly IDR Payment ($)350
payments_madeQualifying Payments Made120
total_paidDerived value= monthly_payment * payments_madecalculated
monthly_rateDerived value= annual_rate / 100 / 12calculated

How It Works

How Public Service Loan Forgiveness Works

PSLF forgives remaining balance after 120 qualifying payments (10 years) while working for a qualifying employer.

Remaining Balance Formula

Balance after N payments = Original x (1+r)^N - Payment x ((1+r)^N - 1) / r

The remaining balance after 120 payments is the amount forgiven. Under IDR plans, payments are based on income rather than loan amount.

Worked Example

A $60,000 loan at 6% with $350/month IDR payments for 120 months.

original_balance = 60000annual_rate = 6monthly_payment = 350payments_made = 120
  1. 01Monthly rate = 6% / 12 = 0.5%
  2. 02Balance growth = $60,000 x (1.005)^120 = $109,164
  3. 03Payments factor = $350 x ((1.005)^120 - 1) / 0.005 = $57,439
  4. 04Remaining balance = $109,164 - $57,439 = $51,725 (forgiven)
  5. 05Total paid = $350 x 120 = $42,000

Frequently Asked Questions

Who qualifies for PSLF?

You must work full-time for a qualifying employer (government, non-profit), have Direct Loans, be on an IDR plan, and make 120 qualifying payments.

Is forgiven amount taxed?

Under PSLF, the forgiven amount is NOT taxable. Under other IDR forgiveness (after 20-25 years), it may be taxable depending on current law.

What if I have not made 120 payments yet?

Keep making qualifying payments. You can track progress through the PSLF Help Tool on studentaid.gov.

Ready to run the numbers?

Open Loan Forgiveness Calculator