Student Loan Calculator

Student Loan Calculator: Compare Your Repayment Routes

You can use this student loan tool to see how much the same amount really costs when you pay it back in different ways, not just one flat monthly amount. Most student loan calculators show a regular payment plan, but they don’t explain how income-driven repayment or the UK’s system works. Also, student loan calculators from refinance lenders tend to focus on what you give up when you refinance federal loans in exchange for a lower rate. This page shows the real trade-offs between each realistic option, including standard repayment, income-driven repayment, extra payments, and refinancing, for a single amount. This way, you can see the real choices, not just one number that hides how differently each option really works.

The Balance We’ll Work With

This page’s U.S. parts will be shown with an example of a $40,000 federal student loan debt at a rate of 6.5%, which was the general rate for federal loans in August 2026. Let us use a borrower with an adjusted gross income of $45,000 to show how income-driven works. The interest rates on the federal student loan calculator are set once a year and may be different for each loan program and disbursement date. Don’t think that this example interest rate will apply to your loan; go to StudentAid.gov to find out.

Route 1: Standard Repayment

This is the standard way for the federal government to get people to pay back their loans. It has a fixed monthly payment for a set amount of time and uses the same amortizing formula that most other loans do.

M = P * [r(1+r)^n] / [(1+r)^n – 1]

At 6.5% for 10 years, or 120 months, on our $40,000 loan:

M = $40,000 ÷ [0.005417 × (1.005417)²²⁰] ÷ [(1.005417)²²⁰ – 1] = $454/month

$54,500 was paid back in total. All together, that’s $14,500 in interest.

Most of the time, standard repayment is the best way to save money on interest because it pays off the loan the fastest and doesn’t require any extensions. So many people who want to borrow money choose student loan calculator income-driven repayment instead because it has the biggest fixed monthly payment.

Route 2: Income-Driven Repayment

Income-driven repayment (IDR) plans on the student loan repayment calculator are different from other types of repayment plans because they don’t base your payment on your loan debt. Instead, they base it on a percentage of your extra income. This means that your payment changes as your income does. After a certain number of payments, any balance that is still due may be forgiven.

Before getting to the numbers, it’s important to know that government income-driven repayment is changing a lot and is changing all the time. There is no longer a SAVE plan because it was thrown out by a federal court in March 2026. As of July 1, 2026, a new Repayment Assistance Plan (RAP) was put in place. It has a new tiered standard plan for new borrowers. According to StudentAid.gov, the only open-ended income-driven plan left for people with federal loans that were disbursed before July 1, 2026, is Income-Based Repayment (IBR). This was confirmed in August 2026. Because these requirements change so often, please check StudentAid.gov/idr to make sure you are eligible and look at your other options before you apply.

To show how this works, we will use IBR, which is the safest option for current borrowers right now. As of now, IBR payments for people who got their first government loan on or after July 1, 2014 (New IBR) are 10% of their discretionary income. After 240 eligible payments (20 years), the loan is forgiven. If you are a single borrower in the 2026–27 award year, your discretionary income is $23,940 (source: StudentAid.gov and HHS poverty guidelines, verified in August 2026) less than 150% of the federal poverty level for your family size. This is your adjusted gross income on the student loan calculator.

In our case, $21,060 of extra income comes from taking $45,000 in AGI away. 10% of $21,060 a year equals $2,106, or $176 a month.

In simple terms, here is the trade-off. This month’s payment of $176 is a lot less than the usual $454, but it’s still not enough to cover the interest on the loan, which at 6.5% is about $217 a month. With this type of payment, the amount can go up instead of down if income doesn’t go up by a lot over time. Any remaining balance after 240 qualified payments can be forgiven under current IBR standards. However, the terms of forgiveness, the way payments are counted, and the availability of the program have changed a lot over the years and are still being questioned publicly and legally. But before you think that you will definitely be forgiven, check the current forgiveness terms at StudentAid.gov. Also, don’t think that the numbers above will still be valid when you reach year 20.

Route 3: Paying Extra (Student Loan Payoff)

With a conventional repayment plan, a student loan payoff calculator goes straight to the principal and lowers every future interest calculation over the life of the loan. If you choose this approach, be sure to tell your loan servicer specifically to apply extra payments to principle and not to just advance your next due date, which is a regular default and will not save you any interest.

Increasing our regular contribution of $454 by $50 a month, bringing it to $504 a month:

The loan will be paid off in approximately 104 months vs. 120, a savings of around 16 months. Total interest paid reduces to about $12,416 vs. $14,500 on the normal plan. Saving about $2,088.

One major caveat: being aggressive with extra payments is not inevitably the best approach for everyone. If you are seeking forgiveness on an income-driven plan, any money paid for extra payments will not be refunded if your remaining balance would have been forgiven otherwise. It only makes sense to pay extra if you’re on a route where you plan to pay the debt off in full anyway, not one where you’re banking on future forgiveness.

Route 4: Refinancing (Read the Trade-Off First)

Before the numbers: If you refinance your federal student loan refinancing calculator with a private lender, the debt will always be private. That means you will never be able to use income-based payments, federal loan forgiveness programs like Public Service Loan Forgiveness, or federal deferment and forbearance protections again. This is the most important thing you need to know before you refinance, but refinance lenders on student loan calculators tend to play it down or leave it out completely.

Having said that, here is the math. Pay off the $40,000 loan with a private loan with a cheaper rate of 5.0% for 10 years:

M = $40,000 ÷ [0.004167 × (1.004167)²²⁰] ÷ [(1.004167)²²⁰ – 1] = $424/month

Totally interested? About $10,916. Or $14,500 if you get the standard federal plan. You’ll really save about $3,584 if you pay off the loan on time at this rate.

Most of the time, refinancing is the best option for people with private or federal loans who make a steady, high income and have no plans to use income-driven repayment or government forgiveness programs. You shouldn’t do this if you want to be able to change your payments based on your income in the future. Once you refinance, you can’t do that again. This is just general information, not advice, and it doesn’t list any refinancing lenders.

Compare All Four Routes

Here’s every route on the identical $40,000 balance:

Anyone who wants to borrow money can’t take the same road. If you can afford it, making the payment on time will lower the total cost. If your monthly payment is based on your income, you might be able to get out of debt, but it can make it harder to plan your finances. People who don’t want to be forgiven save money by making extra payments. You can get a lower rate by refinancing, but it will cost you every government protection for life.

Student Loans in the UK: A Different System Entirely

If you are in the UK, then none of the above approaches are relevant because UK student loan calculator repayment is not a typical loan.

Repayment is a payroll deduction. A fixed percentage of your earnings beyond a threshold. Just like tax, it is deducted automatically. The amount you really owe has no bearing whatsoever on your monthly deduction. A person who owes £15,000 and a person who owes £45,000 on the same plan and similar salary will pay exactly the same amount every month. Any balance left after a predetermined number of years is completely written off, regardless of the remaining amount.

Which plan you are on depends on where and when you attended school. The current thresholds and terms are set out below (source: GOV.UK, student loan calculator: A Guide to Terms and Conditions 2026 to 2027 and guidelines from HM Revenue & Customs, checked in August 2026):

Here’s a practical example: A Plan 2 borrower earning £35,000 a year pays 9% of the amount over £29,385. So: 9% x (£35,000 – £29,385) = 9% x £5,615 = £505.35 a year, or around £42 a month. If you earn less than the criteria in any given period, there are no repayments deducted at all, no matter the balance.

Here’s the twist that turns the US advice on its head: because UK repayment is income-linked with an ultimate write-off, paying more voluntarily only helps borrowers who are on track to repay their loan in full anyway before the write-off deadline. Projected lifetime earnings for a big proportion of Plan 2 and Plan 5 borrowers indicate they’re unlikely to ever repay the full debt before it’s written off. So further voluntary payments in that circumstance are effectively money that would have been written off anyhow. Before making optional extra repayments on a UK student loan, it’s worth assessing what you’ll probably repay over your lifetime against the write-off date, because the conventional ‘always pay extra’ advice can truly waste money here.

Conclusion

The same student loan calculator balance might be worth wildly different sums depending on the repayment path you take, and the lowest monthly payment path isn’t always the lowest total cost path or the best path for your future prospects. Run your own balance through each route before deciding and treat any income-driven or forgiveness figures as subject to change until you’ve checked them directly at StudentAid.gov or GOV. UK, since both systems have already changed substantially in the past few years and show no sign of settling into their final form any time soon.

FAQs

Q1. How is a student loan payment calculated?

Depends on the trip. Normal repayment is calculated with the amortizing loan formula depending on the balance, rate, and period. Income-driven repayment is dependent on a percentage of your discretionary income (your adjusted gross income minus a poverty-guideline criterion), not your debt at all. UK repayment is a fixed proportion of income above a certain threshold and not dependent on your balance.

Q2. Should I pay extra on my student loans?

It depends upon your path. If you’re on standard repayment and not seeking forgiveness, extra payments save significant money, as indicated above. If you’re on an income-driven plan and you’re looking for forgiveness if your debt would have been forgiven otherwise, extra payments aren’t recouped. If you’re on course to have your debt written off before you’ve repaid it in full, then extra payments can be wasted money in the UK.

Q3. Is refinancing student loans a good idea?

It is a question of whether you might someday require government protections. When you refinance, you lose forever income-driven repayment, federal forgiveness programs, and federal deferment and forbearance alternatives. As you can see above, it can really cut your rate and overall cost but only makes sense if you know you won’t need those federal safeguards later.

Q4. What happens to my balance under income-driven repayment?

The payment is calculated as a percentage of your discretionary income, not the balance, so it could be a lot less than a normal payment and may not clear all the interest that’s building up. There are guidelines (which have evolved significantly in recent years) for the forgiveness of any outstanding amount following a defined number of eligible payments. Check StudentAid.gov for the current terms before counting on any precise forgiveness schedule.

Q5. How do UK student loan repayments work?

Student loan repayment is a payroll deduction of 9% (6% for postgraduate loans) of your income beyond your plan’s threshold. You won’t be penalized for the debt you have, and any leftover balance is forgiven after a certain number of years, between 25 and 40 years depending on your plan.

Q6. Do student loan interest rates change?

Yes. U.S. government student loan rates are set each year per school year and vary by loan type; private refinance rates fluctuate by lender and market conditions. Interest rates are evaluated annually in the UK and are dependent on the plan. You may find that they are linked to measures of inflation and, for some plans, your income level. Don’t take for granted a rate you’ve read elsewhere is still in effect; always check an authoritative, dated source.