Interactive tool

Multifamily Mortgage Calculator

Payment, annual debt service, balloon balance and a year-by-year amortization table for a 5+ unit loan, with an optional interest-only period and the DSCR your NOI implies.

Last updated: 2026-10-07

Loan inputs

Calculate your multifamily loan payment

Loan amount

Interest rate

Amortization

Freddie Mac Optigo fixed-rate term sheets list 30 years as the maximum amortization. HUD 223(f) allows up to 35 years and HUD 221(d)(4) up to 40.

Interest-only period

Loan term (balloon at maturity)

Annual NOI (optional)

Enter NOI to see the implied DSCR

Results

Monthly principal & interest

$30,786

At 6.25% · 30-yr amortization · 10-yr term

Annual debt service (year 1): $369,430
Annual debt service, amortizing: $369,430
Balance at maturity (balloon): $4,211,886 (84%)
Total interest over the term: $2,906,189

Amortization table by year

Year	Debt service	Interest	Principal	Ending balance
1	$369,430	$310,841	$58,590	$4,941,410
2	$369,430	$307,072	$62,358	$4,879,052
3	$369,430	$303,061	$66,369	$4,812,682
4	$369,430	$298,792	$70,638	$4,742,044
5	$369,430	$294,248	$75,182	$4,666,862
6	$369,430	$289,413	$80,018	$4,586,844
7	$369,430	$284,266	$85,165	$4,501,680
8	$369,430	$278,788	$90,643	$4,411,037
9	$369,430	$272,957	$96,473	$4,314,564
10	$369,430	$266,752	$102,678	$4,211,886

Assumptions: monthly interest on a 30/360 convention; Freddie Mac term sheets list Actual/360 as standard, which makes the real payment slightly higher. With interest-only, amortization starts when the IO period ends and runs over the full amortization period you pick. Educational estimate, not a quote or loan commitment.

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resources

Hand-picked next steps — go deeper, compare alternatives, or run the numbers.

Title	Type	Summary	Open
Multifamily Underwriting Basics for 5+ Unit Deals	Guide	Comprehensive underwriting framework for US commercial multifamily acquisitions and refinances on 5+ unit properties.	Read guide
Commercial DSCR Loan Guide for Multifamily	Guide	Commercial DSCR loan guide for US multifamily (5+ units)—how lenders calculate DSCR, thresholds by product, and improvement strategies for apartment financing.	Read guide
Rate Risk and Refinance Planning	Guide	Rate risk and refinance planning framework for multifamily sponsors using agency, bridge, and CMBS executions.	Read guide
Fannie Mae Multifamily Loans (DUS) \| Terms, Rates & How They Work	Loan	How a Fannie Mae multifamily loan works for 5+ unit apartment buildings. DUS lenders, 80% LTV and 1.25x DSCR terms, yield maintenance prepayment, Green and affordable options, and a worked sizing example.	Read guide
FHA Multifamily Loan - HUD 223(f), 221(d)(4) Terms	Loan	FHA and HUD multifamily loans compared: 223(f), 221(d)(4), 223(a)(7) and 241(a) terms, 87% leverage, non-recourse structure, fees, timelines and who each fits.	Read guide
Freddie Mac Optigo Multifamily Loans 2026 \| Terms, DSCR & LTV	Loan	Freddie Mac Optigo conventional multifamily loans for 5+ unit apartments in 2026: $10M+ fixed-rate terms, 75-80% LTV, 1.25x DSCR, prepay, fees, and a worked example. SBL was folded into Conventional Small in April 2026.	Read guide

How to read it

What these numbers mean.

How the multifamily mortgage payment is calculated

A commercial multifamily loan is priced like any amortizing mortgage, but the loan term and the amortization period are usually different. The calculator solves three things:

Monthly P&I = Loan × i ÷ (1 − (1 + i)⁻ⁿ), with i = annual rate ÷ 12 and n = amortization in months
Balance at maturity = the unpaid principal after the payments made during the term; this is the balloon you refinance or repay
DSCR = NOI ÷ annual debt service, shown on the amortizing payment and, for interest-only loans, on the interest-only payment too

Worked example: $5,000,000 loan

Loan $5,000,000, rate 6.25%, 30-year amortization, 10-year term, NOI $450,000.

Monthly P&I ≈ $30,786; annual debt service ≈ $369,430
DSCR ≈ $450,000 ÷ $369,430 = 1.22x
Balance at maturity ≈ $4,211,886 (84% of the loan)
Add 24 months of interest-only: payment ≈ $26,042 for two years (DSCR 1.44x on that payment), then $30,786. The balloon rises to about $4,411,037.

Amortization and term by program

Freddie Mac's Optigo Conventional Small loans offer 5, 7, 10, 12 or 15-year terms, and its fixed-rate term sheets list a 30-year maximum amortization (Conventional Small term sheet, fixed-rate term sheet). HUD's FHA-insured programs run longer: Section 223(f) for existing multifamily allows terms up to 35 years and Section 221(d)(4) for new construction or substantial rehab up to 40 years (HUD multifamily programs). Longer amortization lowers the payment and lifts DSCR, which is one reason HUD execution can support more proceeds on the same NOI. See agency stabilized and FHA/HUD multifamily for how the programs compare.

Use it with the other calculators

Once you know the payment, check the leverage with the loan sizing calculator (which of DSCR, LTV and debt yield binds), screen proceeds against NOI with the debt yield calculator, and plan for an early payoff with the yield maintenance calculator. This tool is for 5+ unit commercial loans; for 1–4 unit rentals use DSCR Authority's calculator.

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Frequently asked questions

How do you calculate a multifamily mortgage payment?

Monthly principal and interest = Loan × i ÷ (1 − (1 + i)^−n), where i is the annual rate ÷ 12 and n is the number of monthly payments in the amortization. A $5,000,000 loan at 6.25% on a 30-year amortization pays about $30,786 a month, or $369,430 a year.

What amortization periods do multifamily loans use?

It depends on the program. Freddie Mac's fixed-rate Optigo term sheets list 30 years as the maximum amortization. HUD's Section 223(f) program for existing multifamily allows mortgage terms up to 35 years, and Section 221(d)(4) for new construction or substantial rehab allows up to 40 years. Banks and debt funds set their own schedules, so confirm with the lender.

How does an interest-only period change the payment?

During the interest-only period you pay only loan × rate ÷ 12. On $5,000,000 at 6.25% that is $26,042 a month instead of $30,786. Amortization then starts and runs over the full amortization period, so the payment steps up and the balance at maturity is higher than on a fully amortizing loan. Freddie Mac's term sheets calculate DCR on an amortizing payment even for interest-only loans.

What is the balance at maturity?

Most multifamily loans have a term shorter than the amortization, so a balloon balance is due at maturity. Freddie Mac's Optigo Conventional Small terms are 5, 7, 10, 12 or 15 years. On $5,000,000 at 6.25% with a 30-year amortization and a 10-year term, about $4,211,886 (84% of the original loan) is still owed at maturity.

What DSCR do multifamily lenders look for?

Freddie Mac's Optigo Conventional Small term sheet lists a 1.25x minimum amortizing DCR for fixed-rate loans, with adjustments by property, product and market. Other programs and lenders differ. Enter your NOI above to see the DSCR your loan implies, then compare it with the lender's minimum.

Why will my lender's payment differ from this calculator?

This estimate uses monthly interest on a 30/360 basis. Freddie Mac's term sheets list Actual/360 as standard, which makes the real payment slightly higher. Servicing fees, insurance and tax escrows, and the exact rate at lock also change the number. Use this for planning, not as a quote.