Real estate math, without the signup

Calculators

• Cap Rate Calculator Enter rent and operating expenses to get net operating income and cap rate — no signup, no email.
• Cash-on-Cash Return Calculator Enter the purchase, the loan and the rent to see what your own cash earns each year — no signup, no email.
• Rental Cash Flow Calculator See every dollar between gross rent and your bank account, month by month and year by year.
• DSCR Calculator Enter the rent, the expenses and the loan to see debt service coverage — and the debt capacity your inputs imply.
• BRRRR Calculator Enter the purchase, the rehab and the refinance to see how much cash is still stuck in the deal.
• Fix and Flip Calculator Enter the purchase, the rehab and the expected sale price to see profit, ROI and the break-even ARV.
• MAO Calculator Enter the ARV and the rehab to get a maximum allowable offer — by the 70% rule or by a target profit.
• Deal Analyzer One property, every number: cash flow, cap rate, DSCR, a multi-year projection, IRR and a sensitivity grid.

All eight calculators are live: cap rate, cash-on-cash, rental cash flow, DSCR, BRRRR, fix-and-flip, the 70% rule and the deal analyzer. Guides are being added through the rest of the build plan. Every tool shares one accounting model, so switching between them never changes a number you already trusted.

Why this site exists

Most real estate calculators want something before they show you a number: an account, an email, a phone number, or a download. That friction is deliberate — the calculator is a lead magnet, not a product.

NoiMath does the opposite. Nothing is gated. Each tool documents the accounting conventions it uses, because two calculators that disagree on whether capital expenditure belongs in net operating income will produce two different cap rates from identical inputs. Ours is defined on the methodology page.