Interest-only loans allow borrowers to pay only the interest part with each loan repayment for a fixed period. During this time, no money is used to pay off the outstanding balance. Once this period ends, repayments rise as both principal and interest payments begin, usually amortized over the remaining loan term, until the outstanding balance hits zero.
Whether you are applying for a personal or a business loan, interest-only payments can help when cash is tight for a while or when you expect higher income later. That being said, they are not risk-free. Payments can jump sharply when principal repayment begins, and some products require a large balloon at maturity. But all in all, this repayment structure provides short-term flexibility for borrowers who can only afford to pay reduced payments during a temporary period of limited cash flow.
Interest-Only Periods and Balloon Payments in U.S. Mortgages and Loans
In the U.S., most home mortgages feature 5 or 10-year interest-only periods. For personal and small business loans, the interest-only period can be much shorter and vary by lender. Some loans also end with a balloon due at maturity instead of switching to amortizing payments.
Save on interest: How extra principal payments can work for you
Some lenders might let you make extra principal payments during the interest-only period. This can help you lower the total amount of interest you pay on the loan, as you can lower the principal amount when you pay extra. However, note that individual lenders may charge prepayment penalties, Check your loan agreements for prepayment rules to make sure there are no penalties or restrictions before making extra payments.
What We Offer
Track your loan repayments by amount and date with our pre-made loan calculator, professionally designed in Excel format. Our template is free, scalable, 100% editable, and comes preprogrammed with vital loan calculations. This way, you don’t have to do any of the heft mathematical calculations yourself!
Our editable template can be instantly accessed in .xlsx, .xltx, and .ods formats, at no charge or fee.
User Input
With a few data prompts from your side, you can start analyzing loan data easily and efficiently in no time!
Open the main sheet, and manually add the following details:
- Loan amount: The lump-sum amount of money loaned or borrowed. Loans vary widely, from major mortgages to modest auto loans.
- Annual Interest Rate (AIR): The fixed-interest rate you are charged (e.g., 5% on a business loan of $250,000)
- Loan term (in yrs): The term or life of the loan: This is the total time you (legally) have to pay back the loan, with interest.
- Interest-Only Period: The duration of the loan term during which you are only paying interest
- Payment frequency: Specify how frequently you will make loan repayments. Biweekly, semi-monthly, monthly, bimonthly, yearly, and quarterly options available.
AIR Vs. APR: What’s the Difference?
Be careful not to confuse the Annual Interest Rate (which we use in our sheet) to APR (Annual Percentage Rate). The difference? While the nominal interest rate reflects the cost of borrowing in terms of interest alone, the APR includes additional costs, such as fees, that may apply to the loan.
What We Calculate For You
Based on this data, this template instantly tells you:
- The total number of payments you must make over the entire loan term
- Your periodic payment for the IO period
- Your periodic payment after the IO period, based on the remaining term
- Interest you shall pay with each repayment
- The interest rate you are charged per payment period (this equals the nominal annual rate (or AIR) divided by the number of payments per year)
- Total interest paid over the full life of the loan
How We Calculate Interest
Our template supports two ways of interest calculation methods, the simple-interest, amortizing (or reducing) method, and the add-on (or flat-rate) method. This allows us to cater to a variety of loan terms & arrangements available to borrowers out there.
Keep in mind that most U.S. loans use simple interest on the remaining balance. Interest is charged on the remaining balance after each repayment, so it decreases over time.
That being said, some markets (especially those outside the U.S) use an add-on (flat) interest method that computes total interest up front on the original amount. Add-on methods usually cost more than simple-interest loans with the same stated rate.
So, Which One’s Better?
Most borrowers prefer the reducing interest rate method. That’s because interest is charged only on the outstanding loan balance, not the original amount. As the balance decreases with each repayment, the interest portion also shrinks. This leads to lower overall interest costs and even allows for faster loan payoff, making it a more flexible and cost-effective option compared to the more rigid flat-rate method.
Analyze Key Loan Data for Interest-Only Loans
A great spreadsheet doesn’t just crunch numbers—it shows you figures that matter most. For every interest-only loan you track, four key values are displayed in large, bold panels so you can instantly grasp the essentials of your loan arrangement.
Grand total
This is the total of all payments made over the loan term—the borrowed amount plus the interest charged. We spotlight this figure upfront so you are aware of your financial commitments at a glance, so you can decide if the loan is worth it for you.
Alongside this, we also highlight:
- Loan Amount – the sum you borrow
- Periodic Installment – your regular repayment
Payment frequency options available in our template:
- Biweekly (26 payments per year)
- Semi-monthly (24)
- Bimonthly (24)
- Monthly (12)
- Quarterly (4)
- Annually (1)
- Total Interest – the lender’s charges across the loan term
As you adjust your inputs, these values update automatically in real time. Compare them across different loan scenarios and sheets to identify the option that minimizes costs and helps you become debt-free sooner.
How To Track Multiple Interest-Only Loans Using Our Template?
You can manage several interest-only loans by creating as many spreadsheet copies as you need. To do this, duplicate the entire main sheet by clicking the Select All button (the small square at the intersection of Column A and Row 1).
Warning! If you copy/paste individual or selected cell ranges, you’ll only copy just the text and formatting—not the programmed formulas. By duplicating the whole worksheet, you are able to preserve all formulas, named ranges, and validation.
Rounding option available!
To keep calculations simple and consistent, monthly payments are rounded to two decimal places. You can also choose to disable this rounding feature. Keep in mind, however, that rounding may create small discrepancies—either slightly understating the total interest paid while overstating the principal, or the other way around. Most schedules handle rounding with a small final-payment adjustment that clears the balance.
Plan Smarter with our Benchmark Sheet
In addition to a main loan-calculating sheet, we also offer a Benchmark Sheet as part of our premade package. You can use it to research or plan your loans by testing different loan amounts & interest rates, and see how these changes affect your monthly payment amount and total cost of borrowing. This feature allows you to quickly compare different loan scenarios side by side and choose the loan repayment plan that suits your budget or financial goals.
Targets Template Users
- Private borrowers looking to maximize cash flow
- Homebuyers seeking lower initial payments
- Private lenders
- Banks & credit unions
- Property investors
- Online lenders & fintech companies
- Business owners & entrepreneurs
