Student Loan Calculator 2026: Monthly Payment & Daily Interest

How Student Loan Interest Works

Understanding how interest accrues on student loans is essential for managing your debt effectively. Unlike a mortgage where interest is calculated monthly, federal student loans use a simple daily interest formula. Your daily interest charge equals your outstanding principal balance multiplied by your annual interest rate, divided by 365.25 days. This means every single day you carry a balance, your loan grows slightly larger.

For example, if you owe $30,000 at the current 6.39% undergraduate federal rate, your daily interest charge is approximately $5.25 ($30,000 x 0.0639 / 365.25). Over a 30-day month, that adds roughly $157.50 in interest alone. When you make your monthly payment, the interest portion is paid first, and whatever remains goes toward reducing your principal balance. Early in repayment, a large share of each payment covers interest rather than principal, which is why the first few years of repayment can feel slow.

During periods of deferment or forbearance on unsubsidized loans, interest continues to accrue. If unpaid interest is added to your principal balance, this is called capitalization, and you effectively start paying interest on interest. Avoiding capitalization whenever possible can save you hundreds or even thousands of dollars over the life of the loan. Use our Loan Repayment Calculator to model different payoff strategies and see how extra payments reduce total interest.

Types of Student Loans

Student loans fall into two broad categories: federal loans issued by the U.S. Department of Education and private loans offered by banks, credit unions, and online lenders. Federal loans come with fixed interest rates, flexible repayment options, and potential forgiveness programs that private loans rarely match.

Federal rates are published annually by Federal Student Aid; the table shows rates for loans first disbursed from July 1, 2026 through June 30, 2027, and the loan limits reflect changes that took effect for enrollment periods starting July 1, 2026. Always exhaust federal loan options before turning to private lenders. Federal loans offer income-driven repayment plans, deferment options, and forgiveness programs that private lenders simply do not provide. Use the College Cost Calculator to estimate your total expenses and determine how much you actually need to borrow, then confirm current rates in our student loan interest rates guide.

Federal Repayment Plans Explained

The federal student loan system offers multiple repayment plans designed to accommodate different financial situations. Choosing the right plan can mean the difference between comfortable monthly payments and financial strain. Here is a breakdown of the major options available to borrowers.

Do not choose a repayment plan from an old SAVE calculator. A March 10, 2026 court judgment ended the SAVE plan, and borrowers should verify current plan availability through StudentAid.gov before switching. The Repayment Assistance Plan (RAP) and a tiered Standard plan started July 1, 2026, and PAYE and ICR are scheduled to end July 1, 2028, when remaining borrowers must move to RAP, IBR, or a fixed-payment plan. Compare these options against your income and PSLF eligibility before refinancing or leaving the federal system.

Student Loan Forgiveness Programs

Several federal programs can eliminate part or all of your student loan debt. Understanding these options early can shape your career and repayment decisions in meaningful ways.

Public Service Loan Forgiveness (PSLF)

PSLF forgives your remaining federal Direct Loan balance after you make 120 qualifying monthly payments (10 years) while working full-time for a qualifying employer. Qualifying employers include government agencies at any level (federal, state, local, tribal), 501(c)(3) nonprofits, the military, public schools and universities, and public health organizations. The forgiven amount under PSLF is not taxable as income, making it one of the most valuable forgiveness programs available.

Teacher Loan Forgiveness

Teachers who work full-time for five consecutive years in a low-income school or educational service agency can receive up to $17,500 in loan forgiveness on Direct Subsidized and Unsubsidized Loans. Highly qualified math, science, and special education teachers qualify for the maximum amount, while other qualifying teachers receive up to $5,000.

Income-Driven Repayment Forgiveness

After 20 to 25 years of qualifying payments on an income-driven repayment plan, your remaining balance may be forgiven under the rules for the plan you are actually enrolled in. The tax treatment of non-PSLF forgiveness can change by year and program, so verify current federal and state tax rules before planning around a future forgiven balance.

Average Student Loan Debt by Degree Level

The amount students borrow varies dramatically based on the type of degree they pursue, the institution they attend, and whether they attend in-state or out-of-state. The figures below are rough illustrative estimates, not official statistics; see our average student loan debt guide for sourced federal benchmarks.

A debt-to-income ratio below 1.0 is generally considered manageable. Financial experts recommend that your total student loan debt should not exceed your expected first-year salary after graduation. Use our Scholarship Calculator to explore ways to reduce the amount you need to borrow, and the SAI Calculator to estimate your Student Aid Index and financial aid eligibility.

Refinancing Your Student Loans: Pros and Cons

Student loan refinancing replaces one or more existing loans with a new private loan, ideally at a lower interest rate. While refinancing can save money, it involves important trade-offs that every borrower should understand before making a decision.

The general rule: never refinance federal loans if you might qualify for forgiveness. If you work in public service or have an income-driven repayment plan with a path to forgiveness, refinancing would eliminate those benefits permanently. Refinancing makes the most sense for borrowers with high-interest private loans, strong credit, and stable income who want to reduce their interest rate.

7 Strategies to Pay Off Student Loans Faster

Paying off your student loans ahead of schedule can save you thousands in interest and free up your income for other financial goals. Here are the most effective strategies for accelerating your repayment.

Use our Loan Repayment Calculator to model exactly how extra payments affect your total interest and payoff date. Even small additional amounts can have a dramatic impact over time.

Student Loan Interest Deduction and Tax Benefits

Borrowers who pay interest on qualified student loans may be able to deduct up to $2,500 of that interest on their federal income tax return, even if they do not itemize deductions. For 2026 tax returns, IRS Rev. Proc. 2025-32 sets the deduction phase-out between $85,000 and $100,000 of MAGI for single, head of household, or qualifying surviving spouse filers, and between $175,000 and $205,000 for married filing jointly (2025: $170,000–$200,000).

This deduction applies to interest paid on both federal and private student loans used to pay for qualified education expenses, including tuition, fees, room and board, books, and supplies. Your loan servicer will send you a Form 1098-E each January showing the total interest you paid during the previous tax year. At a 22% marginal tax rate, the maximum $2,500 deduction saves you $550 in taxes.

Confirm eligibility in IRS Publication 970 before filing. Beyond the interest deduction, consider exploring the College Cost Calculator to plan future education expenses, and the Scholarship Calculator to find awards that reduce your need to borrow in the first place.

Federal vs. Private Student Loans: Making the Right Choice

The decision between federal and private student loans can have lasting financial consequences. Federal loans should almost always be your first choice because of their built-in protections and flexibility. They offer fixed interest rates that never change, income-driven repayment options that cap payments at a percentage of your discretionary income, deferment and forbearance options during financial hardship, and access to forgiveness programs like PSLF and IDR forgiveness.

Private loans become necessary when federal aid does not cover your full cost of attendance. Private lenders like Sallie Mae, SoFi, Earnest, and Discover offer both fixed and variable rate options. Variable rates may start lower than federal rates but can increase significantly over time, potentially costing you more than a fixed-rate federal loan in the long run. Private loans also require a credit check and often a cosigner for students without established credit.

Before taking on private loans, exhaust all other options: federal loans, scholarships and grants, work-study programs, and savings. If you do need private loans, compare offers from at least three to five lenders and pay close attention to the APR, repayment terms, cosigner release policies, and any fees. Some lenders charge origination fees that effectively increase your borrowing cost beyond the stated interest rate.

Understanding the total cost of borrowing is critical for making informed decisions about your education. Use the calculator above to compare different loan amounts and interest rates, and pair it with our SAI Calculator to determine how much financial aid you may qualify for before resorting to loans.