Free Tools
Free multifamily underwriting calculators.
The quick math operators run before a deal earns a real model — loan payments, cap rate, NOI, and a back-of-the-napkin screen. No signup, nothing saved, just answers as you type.
Loan Payment Calculator
Monthly principal & interest, annual debt service, and total interest on a multifamily loan.
Monthly payment
$6,321
Annual debt service
$75,848
Total interest over loan
$1,275,445
Amortization Calculator
A full year-by-year payoff schedule — watch how each payment splits between principal and interest over the life of the loan.
Monthly payment
$6,321
Total interest
$1,275,445
Payoff time
30 yrs
| Year | Beginning balance | Principal | Interest | Ending balance |
|---|---|---|---|---|
| 1 | $1,000,000 | $11,177 | $64,671 | $988,823 |
| 2 | $988,823 | $11,926 | $63,922 | $976,897 |
| 3 | $976,897 | $12,725 | $63,124 | $964,172 |
| 4 | $964,172 | $13,577 | $62,271 | $950,596 |
| 5 | $950,596 | $14,486 | $61,362 | $936,110 |
| 6 | $936,110 | $15,456 | $60,392 | $920,654 |
| 7 | $920,654 | $16,491 | $59,357 | $904,162 |
| 8 | $904,162 | $17,596 | $58,252 | $886,567 |
| 9 | $886,567 | $18,774 | $57,074 | $867,793 |
| 10 | $867,793 | $20,031 | $55,817 | $847,761 |
| 11 | $847,761 | $21,373 | $54,475 | $826,388 |
| 12 | $826,388 | $22,804 | $53,044 | $803,584 |
| 13 | $803,584 | $24,332 | $51,517 | $779,252 |
| 14 | $779,252 | $25,961 | $49,887 | $753,291 |
| 15 | $753,291 | $27,700 | $48,148 | $725,591 |
| 16 | $725,591 | $29,555 | $46,293 | $696,037 |
| 17 | $696,037 | $31,534 | $44,314 | $664,502 |
| 18 | $664,502 | $33,646 | $42,202 | $630,856 |
| 19 | $630,856 | $35,900 | $39,949 | $594,957 |
| 20 | $594,957 | $38,304 | $37,544 | $556,653 |
| 21 | $556,653 | $40,869 | $34,979 | $515,784 |
| 22 | $515,784 | $43,606 | $32,242 | $472,178 |
| 23 | $472,178 | $46,526 | $29,322 | $425,651 |
| 24 | $425,651 | $49,642 | $26,206 | $376,009 |
| 25 | $376,009 | $52,967 | $22,881 | $323,042 |
| 26 | $323,042 | $56,514 | $19,334 | $266,527 |
| 27 | $266,527 | $60,299 | $15,549 | $206,228 |
| 28 | $206,228 | $64,338 | $11,511 | $141,890 |
| 29 | $141,890 | $68,646 | $7,202 | $73,244 |
| 30 | $73,244 | $73,244 | $2,604 | $0 |
Cap Rate Calculator
Divide NOI by purchase price to get the capitalization rate, plus price per unit.
Cap rate
7.12%
Price per unit
—
Enter units to calculate
Napkin Underwriting
The back-of-the-napkin deal screen: NOI, value, DSCR, cash-on-cash, IRR, and equity multiple in seconds — decide whether a deal earns a closer look.
Income
Valuation
Financing & exit assumptions
NOI (annual)
$684,000
Estimated value
$10,523,077
$105,231 / unit
DSCR
1.19×
Cash-on-cash
3.3%
IRR (5-yr hold)
11.9%
Equity multiple
1.71×
Year-1 cash flow
$110,679
Annual debt service
$573,321
Loan $7,366,154 · Equity invested $3,367,385 (down payment + acquisition costs) · EGI $1,200,000
Quick screen only — not investment advice. Assumes a level fixed-rate loan, operating expenses held at the entered ratio, NOI growing at the entered rate, and a sale priced on forward-year NOI at the exit cap rate. Excludes capital expenditures, income taxes, and reserves.
NOI Calculator
Back into net operating income from a cap rate and purchase price.
Net operating income (annual)
$520,000
NOI per month
$43,333
NOI = Cap Rate × Purchase Price
Done with the napkin? Underwrite the whole deal.
These quick tools get you to a go/no-go. KeptDo takes the same deal from broker packet to a full, LP-ready model — T-12 normalization, sensitivity analysis, market comps, and investor reports — in about two hours.
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