David is a Chartered Financial Analyst and a Certified College Financial Consultant (CCFC) specializing in student loan planning and repayment strategies.
This 4-in-1 Student Loan calculator helps you plan your repayment strategy for standard loans. Enter any three values—Loan Amount, Annual Rate, Term, or Monthly Payment—and we will solve for the fourth.
Student Loan Calculator
Student Loan (Amortization) Formulas
i = R / 12 / 100 (Monthly Rate)
n = T * 12 (Number of Months)
Solve for Monthly Payment (M):
M = P * [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Solve for Loan Amount (P):
P = M * [ (1 + i)^n – 1 ] / [ i(1 + i)^n ]
Solve for Term (n):
n = log( M / (M – P*i) ) / log(1 + i)
Solve for Rate (i):
(No direct formula; solved iteratively)
Formula Variables
- (P) Loan Amount: The total principal balance of your student loans.
- (R) Annual Rate: The weighted average Annual Percentage Rate (APR) of your loans.
- (T) Loan Term: The total number of years in your repayment plan (e.g., 10 for standard).
- (M) Monthly Payment: The fixed monthly payment required to pay off the loan.
Related Calculators
- Loan Payoff Calculator
- Personal Loan Calculator
- Debt to Income (DTI) Calculator
- Loan Affordability Calculator
What is a Student Loan Calculator?
A student loan calculator is a tool that models a standard (amortized) repayment plan. It helps you understand the long-term cost of your education and how your monthly payments are calculated. This calculator is designed for fixed-rate loans with a fixed term, such as private student loans or federal loans on the 10-Year Standard Repayment Plan.
Understanding these numbers is the first step to financial freedom. You can see how much interest you’ll pay over the life of the loan and, more importantly, plan how to pay it off. This 4-in-1 tool is perfect for “what-if” scenarios. For example, if you get a raise and can afford a $400 monthly payment, you can solve for (T) Term to see how many *years* faster you’ll be debt-free.
This calculator is *not* intended for Income-Driven Repayment (IDR) plans (like SAVE, PAYE) or graduated repayment plans, which have payments that change over time based on your income, not your loan balance.
How to Calculate Your Student Loan Payment (Example)
-
Identify Loan Variables
You are graduating with a standard 10-year loan:
• Loan Amount (P): $30,000
• Annual Rate (R): 5.5%
• Loan Term (T): 10 years -
Convert to Monthly Terms (i, n)
The formula uses monthly values:
• Monthly Rate (i): 5.5% / 12 / 100 = 0.0045833
• Number of Months (n): 10 years * 12 = 120 -
Choose the Payment Formula
Use the standard formula to solve for Monthly Payment (M):
M = P * [ i(1 + i)^n ] / [ (1 + i)^n – 1 ] -
Calculate the Monthly Payment
Plug in the monthly values:
• Numerator: 0.0045833 * (1 + 0.0045833)^120 = 0.00790
• Denominator: (1 + 0.0045833)^120 – 1 = 0.7297
M = $30,000 * [ 0.00790 / 0.7297 ]
M = $30,000 * 0.010826 = $324.78
Your standard monthly payment will be $324.78.
Frequently Asked Questions (FAQ)
What is the standard repayment term (T)?
For federal student loans, the “Standard Repayment Plan” is 10 years. This is the default plan you are placed on. Private loans often offer a variety of terms, such as 5, 10, or 15 years.
Federal vs. Private Loans: What’s the difference?
Federal loans are funded by the government and come with fixed rates, deferment/forbearance options, and access to IDR plans and loan forgiveness. Private loans are from banks or other lenders, often have variable rates, and offer far fewer protections. This calculator works for both as long as they are on a standard amortization schedule.
How do I find my weighted average rate (R)?
If you have multiple loans with different rates, you can find your weighted average rate to use this calculator. Multiply each loan’s balance (P) by its rate (R). Add all these numbers together. Then, divide that total by your total loan balance (P). This is your weighted average rate.
Should I pay off my student loans early?
It’s a personal decision. If your rates (R) are high (e.g., >7-8%), paying them off aggressively is a great, risk-free return. If your rates are very low (e.g., <4-5%), many financial advisors suggest you might be better off paying the minimum and investing your extra money in the stock market for a potentially higher return.