How Optimal Case works
Answers about what's free, what we store and how to download or delete it, where our figures come from, and how share links work. If your question isn't here, email hello@optimalcase.com.
Available now, no account neededFree account neededSample dataComing later
Using the tools
What's free, and what needs an account?
Every calculator and guide works without an account: rent or buy, net effective rent, the rent qualifier, the cash to buy, affordability, the co-op board worksheet, selling, mortgages, Loan Estimates and property analysis. You need a free account only to save your own apartments in the rental tracker. Accounts are free, and there's no paid plan today.
What do the labels next to each feature mean?
Every feature says what it is before you click. "Available now, no account needed" means anyone can use it. "Free account needed" means you need to sign in, which is free. "Sample data" means the figures are an illustration, not a real property or offer. "Coming later" means it isn't built yet.
Do I need JavaScript turned on?
No. Every tool is a simple form: fill it in and press the button, and the page shows your figures. With JavaScript on, the figures also update as you type.
Which phones and browsers does it work on?
The site is built for phones first and tested in Safari and Chrome on screens from 320 pixels wide, as well as on computers. There's a day and evening theme, and animations stop if your device is set to reduce motion.
Your account and your data
What does an account store?
Your email address, an optional name, what you're mainly here for, and your password, which is kept only as a salted one-way hash. In the tracker, the rentals you add (addresses, costs, dates and your notes) and your priority settings, up to 200 rentals. Only you can see your rentals. The privacy policy has the full list of what we collect and why.
How do I download my data?
Sign in and open Your account, then choose Download your data. You get a file with your account details and every rental you've logged. From the tracker you can also export your rentals to a spreadsheet.
How do I delete my account?
Sign in, open Your account and choose Delete your account, then type DELETE to confirm. Your account, every rental you've logged and your sign-in sessions are deleted straight away, and it can't be undone. For anything else we hold, such as messages you've sent us, see the privacy policy for how to ask us to delete it.
I've forgotten my password. How do I reset it?
There's no self-service reset yet, because the site doesn't send email. Email hello@optimalcase.com from the address you signed up with and we'll reset it for you by hand.
Where our figures come from
Where do the tax rates and rules come from?
Mostly from official sources: New York State and City tax and housing agencies, state law and federal agencies such as the CFPB, FHFA and VA. Where no official figure is published, such as physician-loan terms and bank relationship pricing, the page names the published source it relies on and says so. Each rate and rule links to its source with the date we last checked it. The closing-cost tax rates were last checked on 14 October 2026, and the loan programme figures on 14 October 2026. Each guide shows its own date.
How often are the figures checked?
There's no fixed schedule. Every figure shows the date we last checked it against its source, so you can see how recent it is. Before you rely on a figure for a real decision, check that date, follow the source, and confirm it with your attorney or lender.
Which figures are illustrations, not real?
The four sample properties are composites and say "Sample property" on every report. The lender offers are example loan profiles, not quotes. The professionals in the directory are fictional samples. Market yields and growth, the REIT basket, the example portfolio, the sample rentals in the tracker and the memo and members' home previews are illustrations too. Title, attorney and building fees are estimates, and when you test your own property, anything you didn't enter is estimated and listed under What we assumed.
Is this financial, tax or legal advice?
No. It's information to help you understand the numbers and ask better questions. Your attorney, lender or tax adviser confirms the figures for your own purchase or lease.
Getting in touch
How do I contact you?
Email hello@optimalcase.com. If you're a mortgage or real estate professional who'd like to be listed, use the form on the mortgages page.