App builder

Let investors run a rental property calculator
and send you the deals they’re weighing.

Tell Netiva’s agent which numbers your investors care about. It builds a public web app that works out cash flow, cap rate and cash-on-cash return, and saves every emailed breakdown as a lead.

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Starter prompt

Build a public rental property calculator for my investor-focused real estate site. Visitors enter purchase price, down payment, closing costs, repair budget, interest rate, loan term, monthly rent, vacancy rate and yearly expenses, or pick a market to prefill tax, insurance, vacancy and maintenance defaults. Show monthly cash flow, NOI, cap rate and cash-on-cash return on the page. To get the full yearly breakdown by email, visitors give their name, email, investing stage and follow-up consent; save their inputs and results with the lead. My team signs in to a leads list with statuses New, Contacted, Consult booked and Not a fit.

Build it in Netiva Paste the prompt into a new workspace and adjust it to your business.
Overview

Who this rental property calculator is for

Investors who find an agent or coach online want to test a rental before they book a call. A blog post about cap rates doesn’t let them plug in their own price, rent and loan terms, and a downloadable spreadsheet tells you nothing about who used it. A real estate investment calculator built with Netiva runs the numbers on your own site — net operating income, cash flow, cap rate and cash-on-cash return — using the tax, insurance and vacancy defaults you set for your market, then saves each emailed result as a lead with the deal attached.

Key features

What your rental property calculator can do

  • Cash flow and return metrics

    Visitors enter the price, financing, rent and expenses for a rental and watch net operating income, monthly cash flow, cap rate and cash-on-cash return update as they type. Switch to the code view to check each formula.

    • Loan payment worked out from rate, term and down payment
    • Vacancy, management and a maintenance reserve applied as a percentage of rent
    • Cash invested counts down payment, closing costs and repairs
    • A plain-language note under each result explaining the math

  • Market defaults you maintain

    Keep a collection of the markets you serve with typical property tax rates, insurance, vacancy, management fees and a maintenance reserve. Visitors pick a market and the calculator prefills those fields, which they can still overwrite.

    • One record per city, county or neighborhood you cover
    • A last-reviewed date shown next to every default
    • Saved view of markets sorted by the oldest review date
    • Collection assistant to tidy source notes across many rows

  • Emailed breakdowns that become leads

    Headline numbers stay open to everyone. For the full yearly breakdown, a visitor leaves a name and email; the app sends the summary and saves the lead with the deal they ran, so your follow-up starts from their numbers.

    • Consent checkbox and investing stage on the request form
    • Each lead linked to every scenario they submitted
    • An email to you as soon as a new request arrives
    • A signed-in leads list with follow-up statuses for your team

  • Worked example pages

    Publish sample deals — a single-family rental, a duplex, a fourplex — as pages from a collection, each with your commentary and dated assumptions. New examples show up on the list page as soon as you add them.

    • An example list page and a detail page for every deal
    • An “Open in calculator” button that loads the example’s numbers
    • The date the rent and rate figures were current, on each page
    • First drafts of write-ups from the collection assistant
Data model

The collections behind it

Netiva keeps your records in built-in collections. Here’s a starting structure — the agent adapts it to your prompt, and you can change it any time.

Markets

The areas you serve, with the defaults the calculator prefills for each one.

  • Name (required) City, county or neighborhood, with its state Text
  • Property tax rate (required) Percent of assessed value per year; assessed value often differs from the price Number
  • Insurance per year (required) Typical landlord policy for a small rental Number
  • Vacancy rate (required) Percent of gross rent Number
  • Management fee Percent of collected rent; blank for self-managed Number
  • Maintenance and capex reserve (required) Percent of gross rent set aside for repairs and replacements Number
  • Last reviewed (required) Date
  • Source notes Where each default came from Paragraph

Leads

People who asked for the full breakdown, with their investing stage and follow-up status.

  • Name (required) Text
  • Email (required) Text
  • Investing stage (required) First rental, Own 1–4 doors, Own 5+ doors Text
  • Timeframe Buying now, Within 6 months, Just learning Text
  • Follow-up consent (required) Yes or No, from the request form checkbox Text
  • Status (required) New, Contacted, Consult booked, Not a fit Text
  • Source page Calculator, an example page or a course lesson Text
  • Requested at (required) Date & time

Scenarios

Each set of numbers a visitor sent, stored so your team can sort them and load one back into the calculator.

  • Lead (required) Relation to Leads
  • Market Blank if the visitor typed every default by hand Relation to Markets
  • Purchase price (required) Number
  • Down payment (required) Amount put in, before closing costs and repairs Number
  • Interest rate (required) Percent per year Number
  • Loan term (required) Years Number
  • Monthly rent (required) Total across all units Number
  • Cash-on-cash return (required) Yearly pre-tax cash flow divided by cash invested Number

Example deals

Sample rentals you publish as worked examples, each on its own page.

  • Title (required) Text
  • Property type (required) Single-family, Duplex, Triplex, Fourplex Text
  • Market (required) Relation to Markets
  • Purchase price (required) Number
  • Monthly rent (required) Number
  • Photo Image
  • Write-up (required) Your commentary on the numbers and assumptions HTML
  • Figures as of (required) When the rent, rate and expense figures were current Date

Required field. Types are Netiva collection field types.

Screens

Pages and screens to start with

A typical first version. Ask the agent for more, or annotate the preview to change any of them.

  • Calculator

    Inputs grouped into purchase, loan, income and expenses, with a market picker that prefills defaults and results that update as visitors type.

    Public

  • Breakdown request

    The form for the yearly breakdown: name, email, investing stage and consent, with an estimates notice just above the submit button.

    Public

  • Worked examples

    Sample deals listed with property type, market and the headline return, so a visitor can open the one closest to the rental they’re weighing.

    Public

  • Example deal

    One sample rental with its photo, your write-up, the dated figures and a button that opens the calculator with its numbers loaded.

    Public

  • How the numbers work

    Every formula written out, why property tax starts as an estimate from the price, and what the results leave out: income taxes, depreciation and repairs beyond the reserve you set.

    Public

  • Calculator leads

    Requests newest first with investing stage, consent and status, plus the scenarios each person ran and the market defaults your team edits in a grid.

    Your team
How it works

From prompt to a live rental property calculator

  1. Decide which numbers to show

    Tell the agent which inputs visitors fill in, which results stay open and which arrive with the emailed breakdown. It drafts the calculator page and collections for markets, leads and scenarios.

  2. Load your market defaults

    Add the areas you work in with tax, insurance and vacancy figures in the collection grid, and note where each figure came from so you know what to recheck later.

  3. Test with a deal you know

    Enter a rental you’ve already run in your own spreadsheet and compare the results in the live preview. If a number is off, annotate the preview or read the formula in the code view and ask for a fix.

  4. Publish and link it

    Publish in one click, link the calculator from your blog, listings and course pages and turn on the new-lead email. Checkpoints let you roll back if a formula change goes wrong.

Why Netiva

Netiva vs a traditional build

Building a rental property calculator with Netiva compared with a traditional build
Criterion With Netiva Traditional build
Publishing a worked example Add the deal as a row and its page publishes with your write-up, the figures and the date they were current A one-off page per sample deal, with the numbers retyped into the copy and no note of when they were current
Capturing calculator leads Each request saved as a lead with the scenario behind it, and an email to you when it arrives A spreadsheet download behind a form tool, with no record of the numbers each person used
Getting started Describe what you need in chat and watch it take shape in a live preview Hire developers, or stitch together templates, plugins and a hosting plan
Content and data Built-in collections with nine field types, bound straight to your pages Set up and connect a separate database or CMS
Making changes Ask the agent; every change is checkpointed and reversible File a ticket, wait for a sprint, redeploy
Hosting and domain Global hosting and automatic SSL; connect a custom domain from the Starter plan Buy hosting, then install and renew SSL certificates yourself
Code ownership Clean production code you own and can export Locked into a template, plugin or agency setup
Examples

Ways teams use it

  • An agent who helps buyers house hack

    Buyers planning to live in one unit of a duplex or fourplex need numbers that count rent from the other units only. The agent asks for an owner-occupied option, and leads arrive with the price range they’re already considering.

  • An investing coach with an online course

    The calculator sits next to lessons on cap rate and cash flow. Students open the worked examples and change one input at a time, while the coach sees each lead’s investing stage before offering a strategy call.

  • A local investor meetup organizer

    Attendees open the calculator on their phones and run the deal being presented that evening. The organizer keeps defaults for the counties the group covers, and anyone who wants the full breakdown gets it by email.

Good to know

Before you build

  • Present every result as an estimate

    Results depend on what visitors type and the defaults you set. Label them as estimates on the page and in the email, send people to a lender for actual loan terms and keep investment or lending advice out of the calculator.

  • Market data comes from you

    Netiva doesn’t supply rents, tax rates or insurance quotes. Enter defaults you can back up and date them, or connect a rental data provider’s API with your own key. Tax rates and premiums change, so review them on a schedule.

  • Keep example returns honest

    If you sell coaching or courses, don’t present sample deals as the returns students should expect. In 2021 the FTC warned businesses, including investment coaching companies, that misleading earnings claims can bring civil penalties.

  • Marketing emails to calculator leads

    Newsletters or deal alerts you send to leads later are commercial email under CAN-SPAM. They need your valid postal address and a clear way to unsubscribe, and opt-out requests have to be processed within 10 business days.

Compliance note

Results from this calculator are estimates built from the numbers each visitor enters and the defaults you set. They aren’t financial, investment or lending advice, and actual loan terms, taxes and expenses will differ. Put that statement on the calculator page, the worked examples and the emailed breakdown. The app does the arithmetic you describe; it doesn’t judge whether a deal is sound.

FAQ

Questions about building a rental property calculator

Which formulas does the rental property calculator use?

The ones you describe to the agent. A common setup: net operating income is rent after vacancy minus operating expenses such as tax, insurance, management and a maintenance reserve, before any loan payment; cap rate is NOI divided by the purchase price; cash flow is NOI minus yearly principal and interest; and cash-on-cash return is that yearly cash flow divided by the cash invested, such as the down payment, closing costs and upfront repairs. You can read each formula in the code view.

Can the calculator handle a duplex, triplex or fourplex?

Yes, if you ask for it. The agent can add a rent field for each unit and total them before vacancy is applied, so a fourplex with uneven rents still adds up. For buyers who plan to live in one unit, an owner-occupied option can leave that unit’s rent out of the income. Financing for an owner-occupied two- to four-unit home often works differently, so point those buyers to a lender.

Where do the default tax, insurance and vacancy numbers come from?

From you. The Markets collection holds the defaults for each area you serve, and visitors can overwrite any prefilled field. Netiva doesn’t supply rent, tax or insurance data. If you pay for a rental or property data provider, the app can call its API with your key stored securely; otherwise, review your figures regularly and show the last-reviewed date.

Does a real estate investment calculator include taxes or depreciation?

Not unless you ask for it, and even then it’s an estimate, not tax advice. Net operating income leaves out loan payments, depreciation and income taxes, and cash-on-cash return is normally measured before income taxes. Say so on your methodology page and suggest visitors take tax questions to their CPA or tax preparer.

Will the calculator work on phones at a meetup or seminar?

Yes. Netiva builds web apps that run in the browser, including on phones, so attendees open your link and start entering numbers without installing anything. It doesn’t produce iOS or Android store apps. Keep each input group short for small screens, and check the layout in the live preview before the event.

Which Netiva plan do I need to run the calculator on my own domain?

You can build and test the calculator on the free plan in the live preview. Connecting your own domain needs the Starter plan or higher, and higher plans add capacity and features. Calling an outside API, such as a rent data feed, works on every plan. Check Netiva’s pricing page for the current plans before you link the calculator from your main site.

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Drafted with AI assistance from Netiva’s product pages and reviewed by the Netiva team. Example data models, screens and prompts are illustrative starting points, not customer projects.

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