Calculate rent increases, screen tenants, analyze your ROI, estimate deposit deductions, and more — all free, no signup required.
Start with the Rent Increase Calculator →Current rent, tenant income, property details — whatever the situation requires. Simple inputs, no jargon.
Your rent increase, screening verdict, ROI, deposit deductions — calculated instantly in your browser.
Every result includes a plain-English explanation and a clear verdict — so you always know what to do next.
Most landlord tools are buried inside expensive property management software or built for real estate agents — not independent landlords. These calculators are built specifically for people who own rental property and need fast, accurate answers: Is this tenant qualified? How much can I raise the rent? What's my actual return? How much of this deposit can I keep? Every answer comes in plain English, not accounting jargon.
I bought my first rental property in 1985 — a fixer-upper in the Detroit metro area — and I've been running numbers on rental real estate ever since. Over four decades of buying, rehabbing, and managing properties, I've used every landlord tool I could find: spreadsheets, paid software, online calculators buried in real estate blogs. Most of them had the same problem: they were built by people who understood math, not people who had actually dealt with a tenant who stopped paying, a water heater that failed on Christmas, or a security deposit dispute that ended up in small claims court.
Rental Owner Calc is built differently. Every calculator on this site comes with my actual perspective on how to use the number it produces — not just what to enter in the fields, but what the result actually means for how you run your property. The ROI calculator includes a section on why maintenance reserves are almost always too low. The tenant income screener includes a guide to handling non-traditional income under the Fair Housing Act. The security deposit tool includes a detailed breakdown of normal wear and tear vs. actual damage, based on what actually holds up in court.
These tools are free because I believe every landlord — whether you own one house or a growing portfolio — deserves access to the same analytical rigor that professional property managers use. You don't need an MBA or a property management company to make smart decisions. You need clear numbers and the context to understand what they mean.
Each calculator on this site is designed to solve a specific decision a rental property owner has to make. Here's a quick guide to matching the right tool to the right situation:
Evaluating a potential purchase? Start with the Landlord ROI Calculator. Enter your realistic purchase price, financing terms, and projected expenses to get cash-on-cash return, cap rate, and monthly cash flow. Don't skip the guide section on the page — it explains why your maintenance reserve number matters more than almost any other input.
Reviewing a new rental application? Use the Tenant Income Screener to check whether the applicant meets your income threshold, and review the guide below the tool for advice on handling non-traditional income sources consistently and legally.
Approaching a lease renewal? The Rent Increase Calculator shows you the annual revenue impact of different increase scenarios and gives you state notice requirements to work from.
Processing a move-out? The Security Deposit Deduction Estimator helps you itemize damages and calculate what portion of the deposit you can legitimately keep. Read the wear-and-tear guide on that page before you finalize any deductions.
Dealing with a late payment? The Late Fee Calculator calculates what's owed based on your lease terms, grace period, and state rules. The guide explains the legal distinction between enforceable late fees and punitive penalty clauses that courts may strike from your lease.
Unit sitting empty? Run the Vacancy Loss Calculator to see the real per-day cost of vacancy including carrying costs — then read the guide on when to lower your asking rent vs. when to hold.
Rick has been buying, rehabbing, and managing rental properties in the Detroit metro area since 1985. He holds a real estate license and a California general contractor license, and worked directly alongside a distressed asset investor during the 2007–2008 housing crisis. He built Rental Owner Calc to give independent landlords access to the same analytical tools that professional property managers use — for free, with no signup required. Read the full story →