AI tools we build

Why build one tool per job instead of one big dashboard?

General-purpose calculators try to serve everyone and end up serving nobody. A rental underwriting model needs different inputs, different defaults and a different verdict than a flip budget, a lease audit or a listing description. So instead of one bloated dashboard with forty tabs, we ship separate tools that each do a single job to a professional standard, with the assumptions written down where you can argue with them.

Every tool in this collection shares the same engineering spine: the maths runs server-side from a fixed formula set rather than being improvised by a language model, the output is reproducible from the inputs, and anything a lender or partner would question is shown rather than hidden behind a single score. Where AI is used, it is used for the narrative — reading the numbers back to you, flagging risks, suggesting what to verify next — never for arithmetic.

What do you get on this site?

Rental property underwriting

DealUnderwriter is the rental side of the portfolio. Enter purchase price, rent, financing, taxes, insurance and HOA, and it returns cap rate, cash-on-cash return, DSCR, net operating income, monthly cash flow, expense ratio, gross rent multiplier and the 1% rule, plus a conservative buy-or-pass verdict with the specific risks that would make a lender hesitate. Two full underwrites a day are free with no signup — start with the free rental property underwriting calculator.

Pipeline, presets and investor-ready exports

Pro turns a one-off calculation into a workflow: unlimited underwrites, a saved deal pipeline you can sort and compare side by side, reusable underwriting presets so your vacancy, maintenance and management assumptions are applied consistently across every deal, branded PDF exports for lenders and partners, and shareable read-only deal links. The full feature list and price sit on the Pro pricing page.

Market context

Underwriting a deal in isolation tells you whether the numbers work; it does not tell you whether the market is sane. Our city-by-city rental underwriting pages cover typical price points, rent-to-price ratios and the expense assumptions that tend to bite in each market, and the rental investing blog works through the benchmarks — DSCR requirements, expense ratio ranges, cap rate versus cash-on-cash, BRRRR sequencing — in long form with worked examples.

How do you choose the right tool?

Start from the decision you need to make this week. If the question is "should I offer on this rental, and at what price?", you are in the right place. If the question is about a different asset class or a different stage of the deal, one of the sibling tools above will fit better, and they all share the same account and billing conventions so nothing is a surprise. If you cannot tell which one applies, email us through the contact page and we will point you at the right one — including telling you when none of ours is the answer.

Who builds and maintains these tools?

Arend from Dealunderwriter reviews the formulas, the defaults and every published article. That matters for software that produces numbers you will put in front of a lender: when a figure looks wrong, there is a person who can explain exactly how it was derived and change it if the underlying assumption is genuinely off. Feature requests, disagreements about a default and bug reports all go to the same inbox.

Common questions about our tools

Is the rental underwriting calculator free to use?

Yes. Two complete rental underwrites per day are free with no signup and no card. You get cap rate, cash-on-cash return, DSCR, NOI, monthly cash flow, expense ratio, gross rent multiplier, the 1% rule and a buy-or-pass verdict on every free run.

What does Pro add on top of the free tool?

Pro adds unlimited underwrites, a saved deal pipeline with side-by-side comparison, reusable underwriting presets, branded PDF exports for lenders and partners, AI deal review and shareable read-only deal links.

Does AI do the maths behind the numbers?

No. Every figure is computed server-side from a fixed formula set, so the same inputs always return the same output. AI is only used for the narrative: reading the numbers back to you, flagging risks and suggesting what to verify next.

Which tool should I use for my deal?

If you are deciding whether to offer on a rental property and at what price, use the rental underwriting calculator on this site. For a different asset class or a different stage of the deal, pick the sibling tool listed above that matches that job.

Do the tools share one account and one subscription?

Each tool has its own subscription, but all of them follow the same account, billing and cancellation conventions, so nothing about signup, invoicing or cancelling works differently from one tool to the next.

Can I cancel Pro at any time?

Yes. You can cancel from the account page at any time and keep access until the end of the period you already paid for. The refund policy explains how charges and refunds are handled.