ListCalc — every calculator you need.
Instant. Private. Free.

Built for speed, not for page views

There is no “Calculate” button to hunt for and no reload between you and the answer. Type a figure, change your mind, drag a number up and down — the result keeps pace. Start with the mortgage calculator, which shows how much extra payments really save, generates a printable report, and exports your full amortization schedule to CSV. The same approach runs through the whole library, from finance and health to construction and math.

Private because of how it is built

Privacy here is not a policy promise — it is an architectural one. The math is plain JavaScript that ships with the page, so your salary, your medical numbers and your project costs are computed on your own hardware and then forgotten. There are no analytics on what you calculate, and no “unlock the full result” walls — you get the whole answer, free, every time. There is no advertising on ListCalc today; if that ever changes, ads will sit in fixed slots that never cover your answer, never interrupt it, and never receive anything you type. An optional free account exists purely to sync the history you choose to save across your own devices; skip it and nothing changes about the answers you get.

Show the work, not just the number

A number you cannot check is a number you cannot use. Every calculator states the formula it applied, walks through a worked example with real figures, and explains each input in plain language — so you can sanity-check the result before you take it to a lender, a doctor or a client. Where a topic needs more room than a results panel allows, there is a matching guide in the blog that covers the assumptions, the edge cases and the mistakes people usually make.