What this calculator shows
You get three numbers: the monthly principal-and-interest payment, total interest over the life of the loan, and the loan amount you entered. That's the core of any fixed-rate mortgage, whether it's on a rental or your own home.
What it doesn't show is your full monthly cost. On a rental, property taxes, insurance, HOA dues and sometimes mortgage insurance sit on top of this payment, and they can be a big share of it. Leave them out and a deal can look like it cash-flows when it doesn't. The full calculator adds them so you see the whole payment (PITI), and the long-term rental calculator puts that payment against your rent.
How investment property loans are different
Bigger down payment. Conventional loans on investment properties require more equity than owner-occupied loans. For a conventional investment purchase, Fannie Mae and Freddie Mac allow up to 85% loan-to-value on a one-unit property, so at least 15% down, and up to 75% on a 2- to 4-unit property, so at least 25% down. If you'll live in one unit of a 2- to 4-unit building, conventional rules can allow much less down. FHA, VA, DSCR and commercial loans use their own rules. Individual lenders can ask for more. Get current terms from your lender.
Higher rates. Lenders generally price investment loans above owner-occupied loans because the risk is higher. Get an actual quote, and don't assume your home loan rate carries over.
How rent counts. For a conventional loan, lenders typically count only part of the expected rent toward qualifying. Fannie Mae's Selling Guide (B3-3.8-02, as of October 2026) has lenders multiply gross monthly rent by 75%, with the other 25% treated as an allowance for vacancy and maintenance. So $2,000 of rent counts as $1,500.
DSCR loans qualify on the property instead. A DSCR loan looks at whether the rent covers the payment rather than at your personal income. It's a common route for investors with several properties or self-employed income. The DSCR loan calculator shows the ratio lenders look at.
Short-term money for flips. If you're buying to renovate and resell, you're usually in hard money territory, not a 30-year mortgage. Use the hard money loan calculator for that.
Formula
Monthly payment = loan amount × r ÷ (1 − (1 + r)^−n), where r is the annual rate ÷ 12 and n is the term in years × 12. At a 0% rate, it's simply the loan amount ÷ n.
Each month, interest is the remaining balance × r. The rest of the payment goes to principal, and the balance drops by that amount. Total interest is the sum of those monthly interest amounts over the full term.
On the free version, extra payments, points, interest-only periods and balloons are all set to zero, so you can check the result by hand.
Example
Worked example
Illustrative example. The payment and total interest below use a sample rate and term. They are not a quote from a lender.
The investment property mortgage sample is a fixed loan of $400,000 at 6.5% for 30 years. Interest-only years, balloon, points, extra principal, buydown, taxes, insurance, and a second lien are set to zero so the free headlines are principal and interest only. The first payment is $2,528. Total interest over the schedule is $510,178. The loan amount is $400,000. The engine's first principal-and-interest payment on this sample is $2,528. Taxes, insurance, PMI, DSCR sizing, ARM caps, hard-money draws, and a refinance comparison stay in the paid calculator.
Two levers matter most. A shorter term raises the payment but cuts total interest a lot. A higher rate raises both. A lower payment from a longer term isn't cheaper. It just stretches repayment out, and total interest is where you see the cost.
Contractor assumptions
This calculator doesn't include a renovation. If the loan is meant to cover repairs, include them in the loan amount, or use the hard money calculator, which handles draws.
The rate in the example is a sample, not a quote. Rates change daily and differ a lot between lenders and loan types, so use the rate from your term sheet.
Common pitfalls
Treating principal and interest as the full payment. On most rentals, taxes and insurance add a lot each month. Use the full payment when you compare it to rent.
Assuming your home loan terms. Investment loans usually need more down and carry a higher rate, so plug in numbers from an actual investment loan quote.
What stays on the subscription
A subscription adds the rest of the investor mortgage worksheet: interest-only, ARM caps, balloons, DSCR limits, hard-money draws, seller financing, second liens, PMI, taxes, insurance, extra principal, a refinance comparison, the full schedule, saved deals, and the PDF. The free investment property mortgage calculator is the fixed principal-and-interest case. Standard is $9.99 a month after a 48-hour trial that starts when checkout collects a card. Founding is $5.99 a month for the first 100 subscribers.
The payment is an estimate from the amount, rate, and term you type. It is not a loan approval. Lender fees, reserves, and prepayment rules are outside these three headlines.
Sources
Fannie Mae, Eligibility Matrix (August 5, 2026), https://singlefamily.fanniemae.com/media/20786/display (accessed November 10, 2026).
Freddie Mac, Maximum LTV, TLTV, and HTLTV ratio requirements for conforming and super conforming mortgages, https://sf.freddiemac.com/general/maximum-ltv-tltv-htltv-ratio-requirements-for-conforming-and-super-conforming-mortgages (accessed November 10, 2026).
Questions
How much do I need to put down on an investment property?
For a conventional investment purchase, Fannie Mae and Freddie Mac allow up to 85% loan-to-value on a one-unit property, so at least 15% down, and up to 75% on a 2- to 4-unit property, so at least 25% down. If you'll live in one unit of a 2- to 4-unit building, conventional rules can allow much less down. FHA, VA, DSCR and commercial loans use their own rules, and lenders can ask for more.
Are mortgage rates higher for investment properties?
Generally yes. Lenders price them higher than owner-occupied loans. Get a real quote.
Does rental income help me qualify?
Usually some of it does. Under Fannie Mae's Selling Guide as of October 2026, lenders typically count 75% of gross rent from a lease or the appraiser's rent estimate.
Does this calculator include taxes and insurance?
Not the free version. It shows principal and interest so the math is easy to check. The full calculator adds taxes, insurance, HOA and PMI.
What's the difference between this and a DSCR calculator?
This one shows the payment. A DSCR calculator compares the property's income to that payment, which is how DSCR lenders size the loan.