Student loan calculator — fixed payments versus an income-based model

How to use the student loan calculator

1. Enter the Loan balance, the Interest rate and the Standard repayment term in years.
2. Enter your Annual income and the Income protected from the calculation: the part of income your plan ignores.
3. Enter the Share of the remaining income paid (for example 10%) and your Expected yearly income growth.
4. Set Remaining balance forgiven after to your plan’s number of years, or 0 for none. Choose the Currency.
5. Compare the standard plan’s monthly payment and total interest with the income-based first-year payment, time in repayment, total paid and any balance forgiven.

What it does and when to use it

Student loans can usually be repaid in two broad ways: a fixed payment over a set term, or a payment linked to what you earn. The fixed route clears the loan on a known date. The income-linked route can be easier on a lower salary, but it may take much longer and cost more in total unless part of the balance is forgiven at the end.

The rules keep changing. In the US, the Department of Education says loans made or consolidated from 1 July 2026 move to two plans: the income-based Repayment Assistance Plan and a Tiered Standard plan. Because of changes like these, the calculator does not build in any one plan’s numbers. Instead you enter them, which lets you test the plan you have, a plan you are considering, or a “what if” for a raise.

For the plain fixed payment on any loan, the EMI calculator and amortization schedule give month-by-month detail. If you plan extra payments, the loan prepayment calculator shows the interest saved. To plan a target date for clearing other debts, the debt payoff calculator works from a fixed monthly amount.

How it works

Standard plan. The fixed monthly payment uses the usual loan formula:

Payment = B × i × (1 + i)^n ÷ ((1 + i)^n − 1), where B is the balance, i the monthly rate (yearly rate ÷ 12 ÷ 100) and n the number of months.

Income-based model. Each month:

1. Income for the year = starting income × (1 + growth)^(full years passed)
2. Payment = (income − protected income) × share ÷ 12, never below zero
3. Interest = balance × i is added, and the payment is taken off

This repeats until the loan is paid, the forgiveness year is reached, or 100 years pass. Whatever is left at the forgiveness point is reported as forgiven.

Worked examples

These figures come from the calculator’s own function.

$30,000 at 6.5% over 10 years. Standard plan monthly payment $340.64 and total interest $10,877.27. With the default income figures ($50,000 income, $20,000 protected, 10%, 3% growth, 20-year forgiveness) the income-based model starts at $250.00 a month and repays the loan in 11 years 5 months, with $43,871.87 paid in total and nothing forgiven.

Same loan, no income growth. Income stays at $50,000 and forgiveness is off. The payment stays at $250.00, so repayment takes 16 years 3 months and the total paid is $48,584.59.

A larger loan on a lower income. $60,000 at 6.5%, income $40,000, $20,000 protected, 10%, 3% growth, forgiveness after 20 years. The first-year payment is $166.67, below the monthly interest. After 20 years $67,481.50 has been paid and $94,862.11 is forgiven. The standard plan would cost $681.29 a month instead.

Limits and tips

• Generic model, not plan rules. No caps, interest waivers, family-size adjustments or minimum payments are applied unless you build them into your inputs.
• Income growth is smooth. Real pay rises are uneven, and a job change can move the result a lot.
• Check official figures. Your loan servicer or the government’s student aid service can confirm your actual plan and payment.
• The calculation runs in your browser.