Calculators that work with the network off
Every calculator here is arithmetic on values you type, and all of that arithmetic happens inside your browser. There is no upload step, no queue, and no server that holds a copy of what you entered. That is worth stating plainly on a medical tool, because the alternative is not theoretical: a cloud calculator that touches patient values takes on a compliance burden, and it solves that burden with contracts rather than by not receiving the data.
The practical upshot is that these pages keep working on hospital wifi that has dropped, on a phone in a basement, and on a locked-down workstation that cannot reach much of the internet. Load the page once and the calculation is local from then on.
What is deliberately not here
This collection stops at calculations whose output is a measurement. There are no drug dosing tools, no infusion rate tools, and nothing that suggests a diagnosis or a billing code. Those are useful things, and they are also a different category of software with a different bar to clear, so leaving them out is a choice rather than an oversight.
Creatinine clearance and body surface area sit just inside that line: both feed dosing decisions, but what each one actually reports is an estimate of a physiological quantity, and what you do with it stays with you.
Frequently asked questions
- Do these calculators send anything to a server?
- No. Every calculation on this site runs in JavaScript in your own browser. There is no network request when you type a value, nothing is written to a database or a log, and there is no account. Once a page has loaded it keeps working with the network disconnected.
- Why does each page show the equation instead of just the answer?
- Because a number with no working shown cannot be checked. Every page here prints the equation with your own values substituted into it, alongside a citation for where the equation came from, so you can verify the tool rather than trust it.
- Are there dosing calculators here?
- No, and that is deliberate. Everything in this collection computes a physiological quantity from values you enter. None of it outputs a drug dose or an infusion rate, because that is a materially different category of tool with a materially different risk if it is wrong.
- Can I use these on a hospital workstation?
- That is the case they were built for. Nothing is stored, so values from one patient are not waiting on screen or in local storage for the next person to use that machine. Closing the tab is enough to clear them.
- Which reference ranges do these use?
- Each page states the range it labels against and where that range comes from, and several of them note where modern analysers differ from the figures in older textbooks. Laboratories vary, so treat the label as orientation and your own laboratory's stated interval as authoritative.