2026-09-21 7 min read

Student Loan Income-Driven Repayment Calculator

The income-driven payment, balance behaviour and forgiveness for a student loan. Live calculator with worked steps, charts.

Calculator

Current Loan Balance Help

The payoff balance today, not the original amount borrowed.

Annual Interest Rate(%)

Adjusted Gross Income (per year)

Family Size(people)

people

Repayment Plan

Repayment Period(months)

months

This student loans calculator runs on the standard amortisation model: interest is charged on the outstanding balance each month, and anything extra you enter is applied to principal immediately.

Basis of the poverty figure

The calculator uses 150% of the 2025 federal poverty guideline ($23,475 for one person plus $8,250 for each additional family member). Update the figure annually.

Results

Optimal

Income-Driven Payment

$187.71/month

Capped at the 10% of discretionary income rule.

Standard 10-Year Payment

$552.39/month

Monthly Saving vs Standard Plan

$365

Annual Discretionary Income

$22,525

Income above $23,475 — 150% of the poverty guideline.

Forgiveness Horizon

20 years

240 qualifying payments.

Balance at Forgiveness

$90,859

The payment does not cover interest, so the balance grows.

Amount Forgiven

$90,859

Total Paid Over the Horizon

$45,050

Assessment

Balance grows — forgiveness carries the full amount

Live results update as you type — currently showing income-driven payment of $187.71 /month on 12 payments a year. Replace the defaults with your own quote for an exact comparison.

Visualizations

IDR Payment vs Standard Payment

552Standard 10-year

188Income-driven

Balance Over the Forgiveness Horizon

Formula

Income-driven repayment sets the payment from income rather than from the balance, and caps it at what a standard 10-year plan would require.

Payment = max(0, AGI − 1.5 × poverty line) × plan% ÷ 12, capped at the standard payment

Variables

Symbol	Name	Unit	Description
AGI	Adjusted gross income	currency	Income used by the servicer, usually the prior year’s AGI
Poverty line	Protected income	currency	150% of the federal poverty guideline for the family size
plan%	Plan percentage	percent	5%, 10%, 15% or 20% depending on the plan

Explanation

This is the payment your income supports, whether the balance grows, and how much is projected to be forgiven.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Protect 150% of the poverty guideline for your family size, then take the plan percentage of what remains.

Payment = max(0, AGI − 1.5 × poverty line) × plan% ÷ 12

AGI:$46,000

Family size:1

Protected income:$23,475

Intermediate: $22,525 × 0.10 ÷ 12

Result: $187.71 per month

Step 2

Income-driven payments are capped so they never exceed the standard 10-year payment.

IDR payment = min(plan payment, standard payment)

Plan payment:$187.71

Standard payment:$552.39

Result: $187.71

Step 3

Carry the balance forward at the loan rate for the full forgiveness horizon, subtracting each payment.

Balance at forgiveness = amortised balance after the horizon

Horizon:20 years

Payment:$187.71

Result: $90,859 forgiven

Final Answer

$187.71

Worked Examples

See how the calculator works with different scenarios.

Scenario

The student loan income-driven repayment calculator run on the values above, showing the full calculation path rather than only the answer.

Inputs

Balance:48000

Rate:6.8

Calculation

1. Protect 150% of the poverty guideline for your family size, then take the plan percentage of what remains. → $187.71 per month 2. Income-driven payments are capped so they never exceed the standard 10-year payment. → $187.71 3. Carry the balance forward at the loan rate for the full forgiveness horizon, subtracting each payment. → $90,859 forgiven

Result

Income-Driven Payment: $187.71 /month

Interpretation

IDR payment $187.71 per month (10% of $22,525 discretionary income) against a standard payment of $552.39; balance at the 20-year horizon is $90,859.

Understanding Your Result

Your Result: Income-Driven Payment: $187.71 /month

Typical range: Income-driven payments generally land between $0 and 10% of discretionary income; the balance is forgiven after 20–25 years of qualifying payments.

What This Means

This is the payment your income supports, whether the balance grows, and how much is projected to be forgiven.

Why It Matters

IDR payment $187.71 per month (10% of $22,525 discretionary income) against a standard payment of $552.39; balance at the 20-year horizon is $90,859.

Professional Interpretation

IDR payment $187.71 per month (10% of $22,525 discretionary income) against a standard payment of $552.39; balance at the 20-year horizon is $90,859.

How this is calculated

Income-driven repayment sets the payment from income rather than from the balance, and caps it at what a standard 10-year plan would require.

What drives the result

Income-driven repayment sets the payment from your income, not from the balance, so a high debt load with modest income can leave the balance growing while payments are made. Any balance remaining at the end of the forgiveness horizon is discharged — tax-free under Public Service Loan Forgiveness, and historically taxable for income-driven forgiveness outside PSLF.

Recommendations

•Recertify income every year — a missed recertification resets the payment and can capitalise interest.
•Federal student-loan forgiveness under income-driven plans may be taxable; the discharged amount is not cash in hand.

Educational Content

Introduction

Federal student debt has repayment rules that private loans do not: income-driven payments, forgiveness horizons and tax treatment of discharged balances. This calculator applies those rules to your balance, income and payment count so you can see the long-run outcome rather than this month’s payment.

Concept Explanation

Applications

▸Choosing between the standard plan and an income-driven plan

▸Estimating the amount that will be forgiven under PSLF

▸Projecting whether a balance will grow or shrink on IDR

▸Deciding whether refinancing into a private loan is worth losing federal protections

Benefits

•Applies the 120-payment PSLF rule and 20–25 year horizons correctly
•Shows whether the balance grows or amortises on an income-driven payment
•Quantifies the discharged amount rather than just the monthly payment
•Separates tax-free PSLF discharges from potentially taxable IDR forgiveness

Limitations

•Assumes continuous qualifying employment and on-time qualifying payments
•Poverty guidelines and plan percentages change with legislation and are updated annually
•Married filing separately, spousal income and dependants alter discretionary income
•Loan servicer errors and consolidations can reset or complicate payment counts
•Basis of the poverty figure: The calculator uses 150% of the 2025 federal poverty guideline ($23,475 for one person plus $8,250 for each additional family member). Update the figure annually.

Best Practices

•Certify employment and income every year so payment counts stay accurate
•Keep records of every payment, servicer and plan election
•Model the tax on any projected taxable forgiveness before relying on it
•Never refinance federal loans into private credit before modelling what you give up

Common Misconceptions

Myth: Forgiveness always happens after 10 years

Truth: Only Public Service Loan Forgiveness takes 10 years, and only with 120 qualifying payments at a qualifying employer.

Myth: Income-driven payments always cover interest

Truth: Payments can be below the interest charge, in which case the balance grows and the forgiven amount rises.

Practical Tips

•Recertify income on time every year to avoid a payment reset.
•Model the forgiven amount as potential taxable income when planning.

Common Mistakes

Assuming IDR forgiveness is always tax-free

Only PSLF discharges are excluded from federal income tax.

Refinancing federal loans before modelling PSLF

Refinancing permanently removes federal repayment and forgiveness options.

Assumptions

This calculator makes the following assumptions to provide estimates:

Income and family size stay constant: A raise changes the payment at the next recertification.

Limitations

Be aware of these limitations when using this calculator:

Limitation: Assumes continuous qualifying employment and on-time qualifying payments

Limitation: Poverty guidelines and plan percentages change with legislation and are updated annually

Limitation: Married filing separately, spousal income and dependants alter discretionary income

Limitation: Loan servicer errors and consolidations can reset or complicate payment counts

Frequently Asked Questions

Answers to common questions about this calculator.

Why is my IDR payment higher than I expected?

Because discretionary income is based on AGI, and for married borrowers filing jointly it includes a spouse’s income.

What happens if my payment does not cover interest?

The balance grows, and any amount forgiven after the horizon is larger — but so is the eventual tax bill outside PSLF.

Who uses the student loan income-driven repayment calculator?

It is used by borrowers comparing student loan offers, by advisers checking a quote before a client signs, and by lenders and brokers sanity-checking a payment, ratio or fee structure. It sits in the Student Loans group of the Loans & Lending section of Atlascalcs.

How accurate is the student loan income-driven repayment calculator?

Every figure follows directly from the inputs using standard amortisation mathematics, so it is accurate to the quality of the values you enter. Lenders round payments and apply their own day-count conventions, so expect small differences against a formal statement or payoff quote.

How current are the rates and thresholds used here?

The calculator uses the figures you enter, so update the rate to your actual offer or current market quote. Ratio thresholds, poverty guidelines and programme rules reflect the conventions described in the references and change periodically.

Does rounding change the results?

Every calculation runs on full precision and rounds only for display. Lenders round payments to the nearest cent or dollar, so expect a small difference between these figures and a formal statement or payoff quote.

Should I use the payment or the total cost to compare offers?

Use the payment to judge cash flow and the finance charge or APR to judge cost. When two offers differ on both, the all-in cost over the period you expect to hold the loan is the decisive measure.

Can I use this calculator for a business or commercial loan?

Yes. The payment, amortisation, ratio and cost calculators apply the same amortisation mathematics to commercial loans; the difference is in the fees, covenants and collateral rules, which you should enter explicitly.

What information should I have ready before applying?

Your exact rate and term, the fee schedule, any required add-ons, and your gross income and existing monthly obligations. With those five numbers every figure on this page can be tied back to a lender quote.

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Related Guides

Deepen your understanding with these educational resources.

Loan repayment and amortisation guide

How payments split between interest and principal, and how to read a schedule.

Borrowing cost and APR explained

Rate versus APR, points, fees and the cost of a longer term.

Qualifying for credit

The ratios lenders use, and how to improve each one before applying.

Glossary

Technical terms used in mortgage calculations explained in plain language.

Income-driven repayment: A federal student-loan plan that sets the payment as a percentage of discretionary income.
Discretionary income: Income above the protected allowance (usually 150% of the federal poverty guideline) that income-driven payments are calculated on.
Public Service Loan Forgiveness: Discharge of the remaining federal student-loan balance after 120 qualifying payments in qualifying public-service employment.
Capitalisation: Adding unpaid interest to the loan principal so that future interest accrues on the larger balance.

Authoritative References

Trusted sources and standards referenced by this calculator.

Consumer Financial Protection Bureau — Loan options and disclosures Consumer Financial Protection Bureau — What is a debt-to-income ratio? Federal Reserve — Consumer credit (G.19) statistical release Federal Reserve — Consumer credit and leasing guides U.S. Small Business Administration — Loan programmes Federal Student Aid — Income-driven repayment plans Federal Student Aid — Public Service Loan Forgiveness Federal Trade Commission — Consumer credit guidance

Applicable Standards

Level-payment (simple-interest) amortisation, payments assumed in arrearsAPR computed by discounting the actual payment stream to net proceedsDebt ratios computed on gross income for lender comparisonsMoney rounded for display only; all calculations run at full precision

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Page Information

Last Updated:

2026-09-21

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.