Free Student Loan Calculator — The Income-Driven Repayment Trap

Last updated: April 17, 2026

MoneyMath's student loan calculator compares standard repayment with IDR-style payments, balance growth, forgiveness risk, and PSLF timing so borrowers can see the tradeoff between lower monthly payments and total cost.

Free to useRuns in your browserSource-backed assumptions

Free student loan calculator showing the IDR trap. Compare standard vs income-driven plans, see the balance grow, the forgiveness tax bomb, and PSLF timeline.

Use the Student Loan Calculator to compare realistic scenarios before making a money, health, or planning decision.

Adjust the inputs and review the result breakdown so you can see which assumptions matter most.

How to use this calculator

Step 1Enter your starting information. Add the core inputs requested by the Student Loan Calculator, such as amounts, dates, rates, income, weight, or other scenario details.
Step 2Review the calculated result. Read the headline answer first, then scan the supporting breakdown, chart, or comparison table.
Step 3Compare another scenario. Change one input at a time to understand what drives the result and which option is most realistic.

Formula, Sources & Assumptions

Formula

Standard payment uses the amortizing loan formula; IDR-style payment uses discretionary income above 150% of the federal poverty guideline.

Assumptions

IDR availability and forgiveness rules can change; verify the current plan before acting.
The calculator uses a generic IDR-style formula for comparison, not a binding loan-servicer quote.
PSLF eligibility depends on employer, loan type, repayment plan, and qualifying payment history.

Sources

U.S. Department of Education SAVE plan update2026 repayment-plan context for SAVE borrowers.