U.S. Department of Education, Federal Student Aid · reviewed 2026-10-10
What this source supports: Federal student loans carry fixed annual interest rates set annually, with different treatment for subsidized and unsubsidized loans.
Source limit: This is a simple interest estimate; capitalization rules differ by loan program.
These sources support the statements above. They do not show that every person needs this guide. They do not show a specific result.
Limits
This App estimates interest from numbers you enter. It is not financial advice and does not contact your servicer.
This is a simple interest estimate; capitalization rules differ by loan program.
Use current instructions from the responsible organization. This guide is a planning aid, not an official decision or a substitute for qualified advice.
Common questions
What does the App compute?
Estimate monthly interest accrual from your loan balance and rate.
What does the App not do?
This estimates simple interest. It does not replace your servicer statement or give financial advice.
Where do the numbers come from?
You enter every number yourself. The sources support the method and the limits. They do not produce a result for your specific case. Keep the original documents next to the sheet you build.
Before you start
Open the linked source page and keep it beside you.
Gather the values the App asks for:
Current principal balance in dollars.
Annual interest rate percent.
Set aside ten quiet minutes; rushed numbers are the main error this guide prevents.
Free Companion App
The App computes the worked example with your own numbers, in your browser.
APP 1
Student Loan Monthly Interest Estimator
Estimate monthly interest accrual from your loan balance and rate.
This guide is edited for clarity and checked against the sources it links. It is not a substitute for official instructions or qualified advice. A linked source does not show that every person needs this guide.