As a landlord running apartments in Los Angeles, I used to rely on Excel to calculate security-deposit interest. It was time-consuming, confusing, and never as organized as I wanted — especially when saving results as PDFs or keeping up with changing city rates. So I built a tool that makes the whole process simple.

I created SecurityDepositCalculator.com to help both myself and other landlords. It’s completely free, you can register for an account at no cost, and the site is supported only by ads — no fees, no upsells.

The calculator currently supports:

• City of West Hollywood

• Los Angeles Housing Department (LAHD)

• San Francisco Residential Rent Stabilization & Arbitration Board

If your city isn’t listed yet, let me know — I’m happy to add it. My goal is to make security-deposit calculations clear, accurate, and easy for everyone. Always here to help!