Rental Property Calculators (2026): 10 Tools Compared

Running the numbers on a rental before you buy is the step that saves you from a bad deal, and it's also where plenty of tools that turn up in a calculator search do something else entirely.

The ten below are listed alphabetically and in no particular order. Every description comes from each company's own website, as of Nov 2026, and I've grouped them by the job they do, so you can see which ones crunch a deal and which ones keep the books.

Rental calculators and landlord tools side by side

Tool	Type	Good for
Baselane	Landlord banking and bookkeeping	Banking, accounting and rent collection in one
BiggerPockets	Investor community calculators	Free calculators to test a deal's profitability
DealCheck	Deal analysis software	Analysing rentals, BRRRRs, flips and multi-family
Landlord Studio	Landlord management app	Rental accounting, rent collection and tax reports
Mashvisor	Rental data platform	Airbnb and rental data for market analysis
PropStream	Real estate data platform	Property data, lead lists and marketing
Rentastic	Landlord accounting app	Bank feed to a tax-ready landlord report
Rentometer	Rent estimate tool	Rent estimates by address or zip code
Stessa	Landlord finance software	Income, expenses, leases and rent collection
Zilculator	Deal analysis and reporting software	Rental, flip and wholesale analysis with reports

Ten tools for rental property numbers

Baselane

Best for: Multi-property owners who want banking, bookkeeping and automated rent collection in one place, with separate accounts for each property.

BiggerPockets

Best for: New investors who want free calculators to check whether a potential real estate investment is profitable, from a large investor community.

DealCheck

Best for: Investors comparing several properties on a computer, phone or tablet, with comps lookups and profit estimates for each deal.

Landlord Studio

Best for: Landlords who want rental accounting, online rent collection and tenant screening in one app, with a free GO tier once the PRO trial ends.

Mashvisor

Best for: Short-term rental investors and Airbnb hosts who want rental data, comps and analysis to find properties in a market.

PropStream

Best for: Investors and wholesalers hunting for leads, with nationwide property data, built-in tools, AI-powered insights and marketing in one platform.

Rentastic

Best for: Landlords who'd like their bank feed connected and every rent payment and repair sorted into categories automatically.

Rentometer

Best for: Anyone checking what a US house or apartment could rent for, using recent nearby rental data, local comps and market trends.

Stessa

Best for: Owners tracking income and expenses who also want lease drafting, tenant screening, online rent collection and real-time dashboards.

Zilculator

Best for: Agents and investors who analyse deals and want investment reports to share with their buyer clients.

Which of these are calculators, and which keep the books?

Only some of these are calculators, and the vendor pages show the split.

Analyse a deal before you buy. BiggerPockets offers free real estate investment calculators to analyse a potential investment for profitability. DealCheck says it analyses rental properties, BRRRRs, flips and multi-family buildings. Zilculator analyses rental, fix and flip or wholesale deals and produces investment reports. Rentometer answers one question, a rent estimate by address or zip code with local comps, and Mashvisor's page leans on Airbnb and rental data.

Find and research properties. PropStream's page describes real estate data and marketing tools, which is more about finding the deal than doing the maths on it.

Run the rental after you buy. Stessa covers income and expense tracking, leases, tenant screening and rent collection, and Baselane combines banking, accounting and rent collection. Rentastic turns a bank feed into a Schedule E-ready report and Landlord Studio lists rental accounting and Schedule E reports. Schedule E is the US tax form landlords use to report rental income and expenses, and both of those pages name it.

So pick one tool for the maths before you buy and a different one for the books after.

The numbers a rental calculator works out

• Monthly cash flow. The rent coming in, minus the mortgage, insurance, repairs, management and other running expenses.
• Cap rate. Net operating income compared with the property's value, ignoring the mortgage, so you can compare one property with another.
• Cash-on-cash return. A year's cash flow compared with the cash you put in, which shows how hard your own money is working.
• Rent estimate. What similar nearby homes let for. Everything else depends on this one input.
• BRRRR numbers. Buy, rehab, rent, refinance, repeat, where the question is how much cash you can pull back out after the refinance.

The output is only as good as the numbers you enter. A calculator can't know what the roof needs or what the street really lets for, so every result depends on your inputs and on the vendor's own data.

Mistakes that flatter a rental deal on paper

• Guessing the rent instead of checking it against local comps.
• Leaving out empty months, repairs and management.
• Treating a short-term rental forecast as if it were a long-term let.
• Forgetting that a renovation overrun changes every number after it.
• Running one hopeful scenario and stopping there.

If you want software that covers the whole investing process, my list of real estate investing software goes wider. Once you own the place, my guides to the best landlord apps and accounting software for landlords cover the day-to-day.

Do you make a rental property calculator or landlord finance tool? Tool makers can ask to be considered for a featured place on this list.

My plain advice on choosing a rental calculator

Use two tools, not one. Before you buy, run the deal through a calculator with a rent estimate you've checked against local comps, then run it again with worse numbers: lower rent, a month empty, a bigger repair bill. If it still works, it's worth a closer look. After you buy, move the property into a landlord finance tool so the real income and expenses replace your guesses. That's when you find out whether the calculator was right.

None of this is tax or investment advice, so talk to an accountant or adviser about your own situation.

Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.

Frequently asked questions

What does a rental property calculator do?

It takes the rent, the loan and the running expenses you enter and works out numbers such as monthly cash flow, cap rate and cash-on-cash return, so you can see whether a rental is likely to make money.

Are rental property calculators accurate?

They're only as accurate as the numbers you put in. The maths is simple; the hard part is a realistic rent, realistic repairs and realistic empty months.

What's the difference between cap rate and cash-on-cash return?

Cap rate compares a property's net operating income with its value and ignores the mortgage. Cash-on-cash return compares a year's cash flow with the cash you put in, so the loan matters.

Can I use a US rental calculator for a UK property?

You can use the maths, but several of these tools are built around US data, US tax forms and US loans, so check that the rent data and assumptions fit your country.

Do I still need a calculator if I use landlord accounting software?

Usually, yes. Landlord accounting software tracks what's already happening, while a calculator tests a deal before you've bought it.

What is a BRRRR calculator?

BRRRR stands for buy, rehab, rent, refinance, repeat. A BRRRR calculator works out the renovation, the rent and how much cash you could pull back out when you refinance.