When a spreadsheet is the better choice
A spreadsheet you build yourself in Excel or Google Sheets has real advantages, and for some investors it is the right tool.
- Flexibility. You decide every input, formula and layout. If a deal has an unusual structure, you can model it the way you want.
- Cost. Building your own costs nothing beyond the spreadsheet software, which you may already have.
- Little vendor dependence. The model is yours. It relies only on Excel or Google Sheets, not on a smaller tool maker keeping a product available.
- Auditability. You can click into any cell and see how a number was calculated.
- Sync and sharing. A sheet stored in the cloud, such as a Google Sheets file, can be opened on your other devices and shared with a partner. DealLitmus has no cloud sync or team collaboration.
Choose a spreadsheet if you need something DealLitmus does not do. DealLitmus has no tax or depreciation modeling (all figures are pre-tax), no commercial or large multifamily underwriting, and it works in US dollars only. If your analysis depends on any of those, or on a deal structure outside rental, BRRRR and fix-and-flip, a spreadsheet is the better choice.
Where DealLitmus fits
The costs of a spreadsheet are mostly time and risk. It takes time to build and maintain. A formula error can go unnoticed. You often end up with one file or tab per deal, and reports or stress tests exist only if you build them.
DealLitmus is a web app that analyzes rental, BRRRR and fix-and-flip deals with the calculations already built. The free plan includes full analysis for all three strategies, buy-box scoring against your own minimums, 30-year projections and charts, 17 free standalone calculators, share-by-link, and backup and restore to a file. It saves up to 3 deals. There is no account or sign-up. Deals are stored in the browser on your device and are never uploaded.
Pro costs $39 one-time and adds unlimited saved deals, PDF reports through the browser's print-to-PDF, an offer price calculator that works back from a target return to a maximum price, sensitivity tables, side-by-side deal comparison and CSV export of the 30-year projection. Agent costs $99 one-time and includes everything in Pro plus your logo, colors, contact details and custom disclaimer on reports. There is no subscription, and there is a 14-day money-back guarantee. See pricing for the full list.
Some limits to know about. DealLitmus does not import listings from listing websites or the MLS, and it has no property data, sales comps or rent estimates, so you enter the numbers yourself. There is no cloud sync or team collaboration, and deals do not sync between devices automatically. There is no native mobile app; it runs in the browser on phone or desktop. It launched in October 2026 and is made by an independent developer.
The bottom line
If you want control over every formula, need tax modeling or commercial underwriting, or already have a spreadsheet you trust, keep using the spreadsheet. A well-built one can do everything described on this page.
If you would rather not build and maintain formulas, and your deals are rentals, BRRRRs or flips, DealLitmus covers the analysis, projections and buy-box scoring without a build step. You can run a deal through the free rental property calculator and check the results against your own spreadsheet before deciding.