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YOUR PROPERTY. YOUR NUMBERS.

Mortgage Math

by KoozWorks

Products / Mortgage Math
Mortgage & Rental Income CalculatorAndroid

Your numbers, made simple.

Enter what you know. See the mortgage payment, add the property costs you want included, and let rental income show you what is left to cover. Every result updates as you type.

AndroidDownload / UpdateActivation code requiredGet a license or ask for help

Version 1.0.4 · Android 8.0 or later · Offline calculations after activation

JUST ENTER WHAT YOU KNOW

A clear view of the monthly numbers.

Calculate principal and interest from a loan amount, interest rate, and term. Add taxes and insurance for PITI. Use a property price and down payment, or type the loan amount directly. Percentage down payments show their dollar amount. Switching between dollars and percent preserves the equivalent amount using the property price.

Missing details are pointed out without stopping the calculations that already have what they need.

Simple tools for single or multiple units

  • Live principal-and-interest or PITI payments
  • Down payment dollars and percentages convert automatically
  • Optional annual property taxes and homeowners insurance
  • Editable Merced County tax estimate
  • Optional monthly HOA and mortgage insurance
  • Multiple rental amounts and an after-rent monthly total
  • Gross rental yield, independent of loan details
  • Windows desktop or Android phone

Rental income has its own math.

Add rents from one unit or several. Mortgage Math totals them and shows their effect on the monthly amount you need to cover.

Gross rental yield (gross cap) uses annual gross rents divided by property price. It works even if you have not entered the mortgage details.

Gross yield is before expenses and vacancy. A conventional cap rate uses net operating income. Rental income does not change the payment owed to your lender.

Merced County, with room for the details.

Use your actual annual tax bill, or start an estimate with the 1% base rate and add local bond rates and fixed assessments. Enter a taxable assessed value if it differs from the property price.

The 1% base is not a complete parcel-specific rate. Exemptions and one-time supplemental taxes are not automatically included. Merced County tax guidance.

GET STARTED ON ANDROID

Download. Activate. Start calculating.

  1. Tap Download / Update and enter your Mortgage Math activation code.
  2. Open Mortgage-Math-1.0.4.apk from your browser’s downloads.
  3. If Android asks, allow your browser to install this app, then tap Install. You can turn off that permission afterward.
  4. Open Mortgage Math and enter the same code once while connected to the internet.
  5. Find the gold house-and-calculator icon in your apps list. Your calculations work offline after activation.
Download Mortgage Math for Android

Your KoozWorks license

Codes are managed by KoozWorks and assigned to one installation. Downloading the APK does not consume the activation. Contact support if you change phones or clear app data.

Updating the app

Install future releases over the existing app. Keep the existing installation to retain your license; do not uninstall first.

Your numbers stay on your device

Calculations run locally. Internet access is used for license activation and status checks. Mortgage and rent entries are not sent to the license service. Entries are not saved after closing the calculator.