Free Cap Rate Calculator

Why this site exists

Every other free calculator we tested wanted something before it would answer: an email, an account, or a call with a broker. This one answers instantly, and it is free. Eight rental metrics update at once as you type (cap rate, NOI, cash-on-cash, GRM, the 1% rule, DSCR, cash flow and a deal grade), and the arithmetic runs entirely in your browser, so there is no signup, no email, and no backend holding your numbers. Nothing you type is sent anywhere; the only site measurement is aggregate page traffic. It is built for U.S. real estate investors, from first deal to portfolio.

What this site does

Twelve free calculators cover the numbers that decide a real-estate deal: cap rate, NOI, cash-on-cash, GRM, the 1% rule, DSCR, cash flow, a composite deal grade, the two strategy sheets beside them, a mortgage payment tool for buyers, and a prorated rent tool for tenants and landlords. Every one runs in your browser, with no signup, no email, and no account, and it is built for U.S. real estate investors.

Pick the metric you need and its calculator comes to the front, while the other seven keep updating in the background so you can watch the whole deal at once. Change the price, the rent, the down payment, or the interest rate and every figure recalculates as you type. Nothing is submitted, because there is no submit button.

The math is standard. NOI is rent minus vacancy and operating expenses, cap rate is NOI divided by price, DSCR is NOI divided by annual debt service, and cash-on-cash is annual cash flow divided by the cash you invested. Each page explains its formula in plain language, works through a live example, and carries the date it was last reviewed, so you can check the arithmetic instead of trusting it.

Which calculator should you use?

Start with the question you are actually asking. Each scenario below points to the one calculator that answers it, and the rest are one click away in the index below.

You are buying your first rental and need to know whether the price is sane. Start with the cap rate calculator: it turns price and NOI into one number you can compare against your market, and it is the fastest way to see whether a deal is priced for income or for hope.

You have found a property and need to know whether a lender will fund it. Use the DSCR calculator: it divides net operating income by annual debt service and marks the 1.25× line most lenders test, so you learn the answer before you pay for an appraisal.

You are running the BRRRR strategy and need to know how much capital stays trapped after the refinance. Use the BRRRR calculator: it tracks cash left in the deal, equity created, and post-refinance cash flow through the entire buy, rehab, rent, refinance cycle.

You are choosing between two properties and want them side by side. Save each deal with the compare feature: the sheet holds up to three scenarios on your device, ranked across every metric at once, so the trade-offs are visible instead of remembered.

You are buying for monthly income and need to know what actually lands in your account. Use the cash-on-cash calculator: it subtracts debt service from NOI and divides by the cash you invested, which is the only metric that answers what your money earns.

You are a tenant or a landlord splitting a partial month. Use the prorated rent calculator: it turns a move-in or move-out date into the exact partial-month rent, with the daily rate and all three billing methods side by side.

You are pricing the loan itself. Use the mortgage calculator: it builds the full monthly payment from the price, down payment and rate, adds taxes, insurance and PMI, and shows the payoff date, the total interest, and what an extra payment each month is worth.

If none of those fits, the index below lists all twelve calculators with a one-line description of what each one answers.

Every metric has its own calculator

Same live engine, focused explanation, formula, worked example, benchmarks and what moves each number.

How these calculators work

Every calculator here is a static page with its math written in JavaScript that runs on your device. Nothing is uploaded to a server, nothing is tied to an account, and every number recalculates as you type.

That choice is deliberate. Because the formulas ship with the page, there is no upload step and nothing to log. Your inputs never leave the browser tab, the saved scenarios stay in local storage on your own device, and the arithmetic keeps working on a plane or in a basement once the page has loaded.

The formulas are the standard ones. Net operating income is gross rent minus vacancy and operating expenses; cap rate is NOI divided by price; cash-on-cash is annual cash flow divided by cash invested; DSCR is NOI divided by annual debt service; GRM is price divided by annual rent. Mortgage payments use the standard fixed-rate amortization formula, so the debt service you see is the debt service a lender would quote.

Each page then explains itself: the formula in plain language, a worked example with real numbers, benchmark ranges, the inputs that move the metric most, and the date it was last reviewed. Where a metric has a common misuse, the page names it, because a calculator that hides its assumptions is just a black box with nicer typography.