How does a deferral change the loan math?
During the deferral, the calculator assumes no payments and adds each month's interest to the balance. Because the interest is added monthly, the balance compounds: month two charges interest on the original amount plus month one's interest, and so on.
When the deferral ends, the grown balance is amortized over the repayment term you entered, using the same rate. The monthly payment is computed on that larger figure, which is why it comes out higher than it would with no deferral.
Interest accrued during deferral is the grown balance minus the amount originally borrowed. Total interest is all repayment-period payments minus the original amount, so it captures both the capitalized interest and the interest charged on it later.
B = P × (1 + r)^d M = B × r × (1 + r)^n ÷ ((1 + r)^n − 1) Total interest = M × n − P
- B
- balance when repayment begins
- P
- amount originally borrowed
- r
- monthly rate (annual rate ÷ 12)
- d
- deferral months
- M
- monthly payment after deferral
- n
- repayment months (years × 12)
Example: $30,000 at 7.2% with an 18-month deferral
Scenario: Take a $30,000 loan at an illustrative 7.2% fixed rate, no payments for 18 months, then 10 years of monthly repayment. Interest capitalizes monthly during the deferral.
- Monthly rate7.2% ÷ 12 = 0.6% (0.006)
- Balance after deferral$30,000 × 1.006^18 = $30,000 × 1.1136883 = $33,410.65
- Interest accrued during deferral$33,410.65 − $30,000 = $3,410.65
- Monthly payment$33,410.65 over 120 months at 0.6% = $391.38
- Total interest$391.38 × 120 = $46,965.60; $46,965.60 − $30,000 = $16,965.60
- Compared with no deferralWithout deferral the payment would be $351.43 and total interest $12,171.60, so the deferral adds $4,794.00
The 18-month pause adds $3,410.65 to the balance, raises the payment by $39.95 a month and adds $4,794.00 of interest overall.
Some loans capitalize only once, at the end of deferral, which produces a slightly smaller balance than this monthly model.
When should you run a deferral scenario?
Before accepting a delayed-first-payment offer
Retail, equipment and some personal loans advertise a first payment months away. Running the numbers shows what that delay adds.
Planning around school or training
Loans taken while studying often defer payments until after graduation. Seeing the balance at repayment helps you plan your first budget.
Deciding whether to request a hardship deferment
A deferment can be a real lifeline. Knowing the cost lets you weigh it against an alternative such as a reduced payment.
Testing whether to pay interest during the pause
Compare the deferral result with zero deferral months to see how much paying interest as it accrues would prevent.
What do borrowers miss about deferral?
Thinking deferral means interest-free
Unless a subsidy or promotion explicitly covers interest, it keeps accruing. Check the loan terms for who pays the deferral interest.
Counting only the interest accrued during the pause
Capitalized interest is repaid with interest over the whole term. The full extra cost is larger than the deferral interest alone.
Confusing deferred interest promotions
Some store financing charges all the back interest if the balance is not cleared in time. That structure is different from the steady capitalization modeled here.
Forgetting the clock starts at borrowing
Total time to payoff is the deferral plus the repayment term. An 18-month deferral on a 10-year loan means 11.5 years of debt.
Not paying interest when you could
Even small interest-only payments during deferral keep the balance flat. If cash allows, it is one of the cheapest ways to cut the loan's cost.
How fast does the cost grow with longer deferrals?
Each extra month adds a little more than the month before because the balance is compounding. On the $30,000 example, six months of deferral adds about $1,096.33 to the balance, while 36 months adds $7,209.05, more than six times as much.
If you paid only the interest each month during the 18-month deferral, you would spend $3,240.00 ($180 a month) and start repayment owing exactly $30,000. That is less than the $4,794.00 the deferral adds in total interest, because none of that interest gets capitalized and charged interest for another decade.
| Deferral | Balance at repayment | Monthly payment | Total interest |
|---|---|---|---|
| 0 months | $30,000.00 | $351.43 | $12,171.60 |
| 6 months | $31,096.33 | $364.27 | $13,712.40 |
| 12 months | $32,232.73 | $377.58 | $15,309.60 |
| 18 months | $33,410.65 | $391.38 | $16,965.60 |
| 24 months | $34,631.62 | $405.68 | $18,681.60 |
| 36 months | $37,209.05 | $435.87 | $22,304.40 |
Terms used on this page
- Capitalized Interest
- Capitalized interest is unpaid interest that gets added to a loan's principal balance. After capitalization, you pay interest on that interest, which raises both your payment and total cost. It commonly happens with student loans after periods when payments are paused, such as school, a grace period or certain forbearance and deferment periods.
- Amortization
- Amortization is the process of paying off a loan with equal, regular payments that each cover the interest due for the period plus a slice of principal. Early payments are mostly interest; later ones are mostly principal. By the final payment the balance reaches exactly zero, which is how most car, personal and student loans work.
- Compound Interest
- Compound interest is interest earned or charged on both the original principal and the interest that has already built up. Each period's interest is added to the balance, so the next period's interest is a little larger. Over long stretches, compounding makes savings grow faster and unpaid debts grow faster too.
- Interest Rate
- An interest rate is the price of money, stated as a percentage of the balance per year. Borrowers pay it to lenders, and savers earn it from banks. The rate alone does not include fees or compounding, so it can understate the true yearly cost of a loan or overstate a simple comparison of savings accounts.
Deferred Payment Loan Calculator: common questions
What is capitalized interest on a deferred loan?
It is unpaid interest that gets added to your principal. Once capitalized, it is treated as part of the amount you borrowed, so it earns interest too. On a deferred loan, capitalization is what turns a pause in payments into a permanently larger balance and a higher payment once repayment begins.
Will my monthly payment be higher after a deferment?
Usually, yes, if the repayment term stays the same. The payment is calculated on the grown balance. In the example, an 18-month deferral raises a 10-year payment on $30,000 from $351.43 to $391.38. Some lenders instead extend the term to keep the payment level, which raises total interest further. Ask your lender which approach it uses before the deferral ends.
Is it better to pay interest during a deferral?
If you can afford it, paying interest as it accrues is one of the most effective ways to limit the cost. It keeps the balance at the original amount, so nothing is capitalized and your payment after the deferral stays where it would have been. Even partial interest payments reduce what gets added.
How much interest builds up during a 12-month deferral?
It depends on the balance and rate. At 7.2% with monthly capitalization, $30,000 grows to $32,232.73 after 12 months, so about $2,232.73 of interest builds up. A higher rate or larger balance scales that up roughly in proportion. That amount is then capitalized and charged interest for the rest of the repayment term. Paying it as it accrues, about $180 a month in this case, would keep the balance at $30,000.
Do all loans capitalize interest monthly during deferral?
No. Some capitalize monthly, some only once at the end of the deferral, and some programs cover the interest entirely. Monthly capitalization costs a little more because interest compounds sooner. Your loan agreement or servicer can tell you which rule applies; this calculator assumes monthly. The difference between the two methods is modest over a short deferral but grows with longer pauses and higher rates.
Does a deferral hurt my credit?
An approved deferral generally is not reported as a missed payment, because no payment is due. Skipping payments without an agreement is different and can be reported as delinquent. Check your credit reports after a deferral ends to make sure the account shows as current. Keep written confirmation of any deferral agreement in case a payment is reported in error.
How is deferment different from forbearance?
Both pause or reduce payments, and the terms are used most precisely for federal student loans. The main practical difference there is who pays the interest: some federal loans have interest covered during deferment, while interest generally accrues during forbearance. For other loans, the lender's agreement defines what each term means.
Can I shorten the repayment term to offset a deferral?
Yes, if the lender allows it or you simply pay more than required. Paying extra once repayment starts eats into the capitalized interest early, when it would otherwise generate the most new interest. Run a shorter repayment term in the calculator to see the payment that would erase the deferral's added cost.
Why is the total extra interest bigger than the deferral interest?
Because the capitalized interest is repaid over the whole term and accrues interest the entire time. In the example, $3,410.65 is capitalized, but the total interest rises by $4,794.00. The extra comes from charging interest on that capitalized amount for 10 more years. The longer the repayment term, the wider this gap becomes. That is why paying deferral interest, or paying extra early in repayment, saves more than it first appears.
Sources
- Student loans — Consumer Financial Protection Bureau. Accessed October 17, 2026.
- Student loan repayment plans — Federal Student Aid (U.S. Department of Education). Accessed October 17, 2026.
- Regulation Z (Truth in Lending), 12 CFR Part 1026 — Consumer Financial Protection Bureau. Accessed October 17, 2026.
We cite primary sources: regulators, central-bank data and federal agencies. Worked examples on this page are our own calculations, last checked October 17, 2026. See our methodology.