An instrument, not a sales funnel.
Ledger began as a spreadsheet. Not a product, not a startup — a personal Google Sheet with eight tabs, each containing one financial formula, used to make decisions about a mortgage, a car loan, a retirement contribution, and whether a side project would ever break even.
The spreadsheet was shared with friends. Friends shared it with friends. Eventually someone said: "You should put this online." So we did — with one rule: no signup, no ad, no tracking pixel, no email capture, no "premium" version. The math is the product. The math is the whole product.
Every formula used here is standard, published, and centuries old in some cases. The amortization formula has been on bank chalkboards since the 19th century. Compound interest was described by Richard Witt in 1613. Break-even analysis was formalized by economists in the 1930s. We did not invent any of this. We rendered it cleanly.
If a result is wrong, it is wrong in a way you can trace — every variable is visible, every formula is published on the calculator page. If you disagree with an assumption (e.g., the default mortgage rate), change it. The inputs are yours. The math is the math.
Four commitments
we will not break.
01 · No tracking
No Google Analytics. No Facebook Pixel. No session recording. No cookies. The server logs a single anonymized request hash for capacity planning. That is the full extent of our data collection.
02 · No paywall
Every calculator is free. Every formula is visible. There is no premium tier, no "pro" version, no upsell. The project is sustained by its creators because the cost of hosting a PHP application is negligible.
03 · Open math
Every calculator page publishes the formula it uses, with every variable labeled. If you want to verify the result in your own spreadsheet, you have everything you need. If you find an error, we want to know.
04 · No advice
Ledger is an instrument, not an advisor. The calculators produce mathematical outputs from your inputs. They do not consider your tax situation, your risk tolerance, your estate plan, or your emotional relationship with money. For those, hire a fiduciary.