Questions, answered
with the same precision
as the calculators.

Yes. Every calculator on Ledger is completely free, with no signup, no paywall, and no advertisement. The project is sustained by its creators as a public utility.

No. All calculations run either in your browser (via JavaScript) or as a single server-side PHP request. We never persist the numbers you enter, and we do not use tracking cookies. Aggregate, anonymized calculation counts may be logged for capacity planning, but the inputs themselves are never stored.

Our calculators use standard financial formulas (amortization, compound interest, future value of a series, ROI). Results are mathematically exact for the inputs given. Real-world loans may include fees, rounding, or lender-specific adjustments that shift the final number by a small margin. Always verify critical numbers with your lender or financial institution.

Ledger is an educational tool, not a fiduciary advisor. The calculators give you the mathematical foundation for a decision. For tax, legal, or investment advice specific to your situation, consult a licensed professional (CPA, CFP, or attorney).

Monthly compounding (12 times per year) is the default because most loans and savings accounts compound monthly. Use annual (1) for index fund projections, daily (365) for high-yield savings accounts, and continuous for theoretical maximum growth. The difference between frequencies is small at low rates but compounds over long time horizons.

Private Mortgage Insurance is required on conventional loans with less than 20% down payment. Omitting it would understate the true monthly housing cost by $100–400 in the early years. Enter 0% if your down payment is 20% or more, or if you have an FHA loan with a different mortgage insurance structure.

The traditional "4% rule" (from the Trinity Study) suggests withdrawing 4% of your starting balance annually, adjusted for inflation, for a 30-year retirement with a high probability of not running out of money. More conservative planners now recommend 3–3.5%, especially for longer retirements or more conservative portfolios. The calculator lets you adjust this to model different scenarios.

They do — indirectly. If you enter a nominal expected return (e.g., 7% for a stock portfolio), you get nominal results. If you want real (inflation-adjusted) results, subtract expected inflation (typically 2–3%) from your return assumption. A 7% nominal return with 3% inflation is a 4% real return. Both approaches are valid; just be consistent.

Not currently. The calculators are self-contained within Ledger to ensure formula integrity and a consistent experience. If you need embedded financial calculators, there are commercial services that offer them (with tracking and fees). Ledger is free to link to from anywhere.

Check the formula on the calculator page — every variable is labeled. If the formula is correct but the output does not match your manual calculation, there may be a rounding or input parsing issue. Report it through the project's GitHub repository with the specific inputs and expected vs. actual output.