
DealCheck.io
Mashvisor
PropStream
Rehab Valuator
REIkit House Flipping Software
ProAPOD
PropertyMetrics
Analyze any rental property deal in seconds with 18 free calculators: cash flow, cap rate, cash-on-cash, NOI, BRRRR, DSCR and more. No sign-up, no downloads, no paywall, and every result shows the math so you can trust it.

Mailflow.sh
Stackmail is a webmail service whereby you can log in to your emails from any browser at any time!

Which is more popular?
Website, pricing, platforms and company facts side by side.
|
|
|
|
|---|---|---|
| Website | cashflowcalcs.com | stackmail.com |
| Pricing | — | |
| Platforms | — | |
| Company | Startup from the United Kingdom · 1 - 9 employees · 2026 | — |
| Listed in |
In their own words, as submitted to SaaSHub.


CashflowCalcs is a free suite of 18 calculators that lets US rental property investors and landlords analyze any deal in seconds. No account, no downloads, no paywall, and every calculator shows its formula and a worked example, so you are never trusting a black box. Most rental-analysis tools...
No description of StackMail yet.
What each product offers, as listed by its team.


Possible disadvantages
An editorial look at what each product does well and who it suits.


No analysis of CashflowCalcs yet.
Overall verdict
Why this product is good
Recommended for
How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing CashflowCalcs and StackMail.
CashflowCalcs's answer
CashflowCalcs brings the whole rental-property analysis workflow into one free, no-sign-up place. Instead of a single cap-rate or mortgage calculator, it offers 18 connected tools spanning deal analysis, investing strategies, financing, and taxes, and every calculator shows its formula and a worked example rather than acting as a black box. It runs entirely in your browser, the numbers you enter never leave your device, and it stays free with no account and no paywall.
CashflowCalcs's answer
Most rental-analysis tools make you create an account, start a trial, or pay before you can run a single number. CashflowCalcs lets you analyze any deal in seconds with no sign-up, no downloads, and no paywall. It's fast, mobile-friendly, and transparent about the math, so it's ideal for quickly checking whether a deal actually cash flows before you commit time to it or pay for heavier software. It's also honest about its limits: results are clearly labeled as educational estimates, not financial advice.
CashflowCalcs's answer
US-based rental property investors and landlords, especially beginner-to-intermediate investors who want a quick, reliable way to run the numbers on a potential deal. It also fits people weighing their first rental purchase, house hackers, and small-portfolio landlords who need cash flow, cap rate, and financing math without a subscription.
CashflowCalcs's answer
CashflowCalcs started from a simple frustration: every time its founder wanted to quickly check whether a rental property cash flows, he hit a login wall or a "start your free trial" button just to calculate a cap rate. So he built the tool he wanted, a set of free calculators that run the numbers on any rental deal in seconds, right in the browser, with no account and no downloads. It launched in 2026 and has grown into 18 connected calculators covering the full rental-analysis workflow, and it stays free, supported by ads.
CashflowCalcs's answer
It's a static site built with Astro and lightweight vanilla JavaScript for the calculators, so pages load fast and run entirely in the browser. It's hosted on Cloudflare Pages, with Cloudflare handling DNS and analytics. There's no backend or database, which is what keeps it fast and private, since the numbers you enter never leave your browser.
Share your experience with using CashflowCalcs and StackMail. For example, how are they different and which one is better?
When comparing CashflowCalcs and StackMail, you can also consider the following products.

Analyze any investment property on your computer, phone or tablet in seconds. Compare properties, look up comps and find the best real estate deals.
Compare DealCheck.io to CashflowCalcs or StackMail:

A self-hosted, unified webmail client. Connect multiple IMAP/SMTP accounts and manage them all in one clean interface.
Compare Mailflow.sh to CashflowCalcs or StackMail:

Find properties that will make money on AirBnb
Compare Mashvisor to CashflowCalcs or StackMail:

PropStream is an impressive real estate investment software that is creating an impact via providing comprehensive data.
Compare PropStream to CashflowCalcs or StackMail:

Rehab Valuator is an impressive piece of real estate software that is primarily designed for rehabbers, flippers, and wholesalers.
Compare Rehab Valuator to CashflowCalcs or StackMail:

House Flipping & Wholesaling Software to Scale: Comps, ARV, CRM, Investor Websites, Teams, Nationwide Rehab Cost Estimator, Deal Marketing, Owner Info
Compare REIkit House Flipping Software to CashflowCalcs or StackMail: