Spreadsheets that show their work.
Money tools for invoices, taxes, rentals and renovations. Every formula matches its standard definition, ships with a worked example, and is tested before release — one file, one price, yours forever.
8 tools · $0–15 · Excel + Google Sheets + LibreOffice · no macros
Yellow cells are yours. Everything else calculates itself.
- 01 — BUILD
Built to the definitions
Each spreadsheet is built around the textbook formula and a worked example you can inspect.
- 02 — VERIFY
Machine-tested math
Formulas are tested for arithmetic correctness — cap rate = NOI ÷ price, DSCR = NOI ÷ debt service — before release.
- 03 — SHIP
Published with its receipt
Only tools that pass go live. The verification claim stays on every listing, checkable.
The ledger of tools
8 entries · one-time prices
Freelance Invoice Tracker (Free)
invoiced · collected · awaiting · overdueFREE $0 02
Freelance Finance OS
invoices · tax buffer · rates · quarterly tax $5 03
Freelance Quarterly Tax Estimator
payment per deadline · paid · remaining $4 04
Rental Property Investment Analyzer
cap rate · cash-on-cash · NOI · DSCR $9 05
Short-Term-Rental (Airbnb) Deal Analyzer
cash flow · DSCR · break-even occupancy $12 06
Real Estate Investor Toolkit
both analyzers — long-term + Airbnb $15 07
Home Renovation Budget & Project Tracker
budget vs actual · bids · contingency $8 08
Content-Creator Income & Tax Tracker
net after fees · tax set-aside · RPM $7A small shop with receipts
By the Loop is a one-person shop with an unusual amount of rigor behind it: every tool goes through a build-and-test pipeline — the loop — that checks each formula against its standard definition and refuses to ship anything that fails.
The owner makes the calls; the pipeline does the checking. That's why the promise is narrow and checkable: the arithmetic is verified before anything goes live.
What the tools can't do is know whether your rent, occupancy or expense assumptions are realistic. They do the math on the numbers you enter — the judgement stays yours.