NursingCalc is a free set of clinical calculators, reference charts and med-math practice for nursing students and nurses. No accounts, no sign-up, nothing to install. This page explains who is behind it, where the content comes from, how it is checked, and what happens when something turns out to be wrong.
Last updated · How pages are checked
NursingCalc is run by an independent publisher. It is not part of a hospital, a university or a nursing school, and it is not written or signed off by a named panel of clinicians. We would rather say that plainly than borrow authority we do not have.
So the site is built the other way round. Nothing here asks to be trusted on someone’s say-so. Every calculator states the formula it uses and the paper it comes from. Every reference range names the guideline behind it. Every worked example shows its working. If a page cannot point to a primary source for a number, the number does not go on the page.
The work is narrow on purpose: medication math, infusion rates, standard clinical formulas and the reference values nurses look up every shift. Those are areas where the right answer is defined by a published method, which makes them checkable by anyone.
Formulas come from the paper that defined them or the guideline that adopted them: Cockcroft and Gault for creatinine clearance, Baxter and Shires for the Parkland formula, Mosteller for body surface area, Devine for ideal body weight, the CKD-EPI 2021 equation for eGFR. Reference ranges come from bodies such as the American Heart Association, the American Diabetes Association, KDIGO, ACOG, WHO and the CDC. Medication math follows the methods taught in nursing programs and the Infusion Nurses Society standards.
We cite the original, not another website. Where reputable sources disagree, as they often do on paediatric vital sign ranges or on which body weight to use in a formula, the page says so and shows the range rather than picking one figure and presenting it as settled.
Formulas are checked against the source. Each calculator is compared with the published equation and run against worked examples, including unit conversions and edge cases, which is where most real calculation errors happen.
Tables are calculated, not typed. Conversion charts, worked examples and reference tables are generated by code from the same formula the calculator uses, so the table and the calculator cannot drift apart.
Practice problems are tested in bulk. The dosage calculation practice generates problems from realistic drug strengths and checks every answer against an independent recalculation. Before launch the self-test ran 468,000 generated problems with no failures, and the pages were tested in a browser on desktop and phone. How the practice problems work explains the rounding rules and drug data.
Dates mean something specific. “Reviewed against the cited sources” on a page means its clinical content was rechecked against those sources on that date. “Last updated” means the date the page last changed. We do not change a date without changing the page.
It is not medical advice. Nothing here diagnoses, prescribes or recommends treatment for any individual. It does not replace your facility’s policies; where a local protocol differs from a general formula, the protocol wins. It does not replace an independent double-check for high-alert medications, paediatric doses or critical care infusions. And it is not a substitute for assessing the patient. A number outside a range is information, not a decision.
If you think something on NursingCalc is wrong, email info@nursingcalc.com with the page address and what you believe the error is. Reports about formulas, ranges and calculator output go to the top of the list and are checked against the primary source before anything changes. A report that turns out to be mistaken still costs only a few minutes; an error left on a clinical page costs more. Nurses, pharmacists, educators and students who spot something are especially welcome to write.
Substantive clinical corrections are listed here, newest first. Typo fixes and layout changes are not.
| Date | Page | What changed |
|---|---|---|
| 21 Oct 2026 | mcg/kg/min calculator | Replaced a citation that named a drug-interaction reference as the formula source. The formula and results did not change. |
| 21 Oct 2026 | Nursing math cheat sheet | Aligned four reference ranges in the lab table (bicarbonate, fasting glucose, BUN, male creatinine) with the lab values cheat sheet and the full lab values guide, which already agreed. |
| 21 Oct 2026 | BSA calculator | Corrected an FAQ that gave the typical body surface area of a 10-year-old as 1.4 m²; it is about 1.1 m², as the page’s own reference table already showed. |
| 13 Oct 2026 | eGFR calculator | Moved from the 4-variable MDRD equation, which included a race coefficient, to the race-free CKD-EPI 2021 equation recommended by the NKF-ASN task force. Added creatinine in µmol/L. |
| 13 Oct 2026 | Pregnancy due date calculator | Fixed a date-handling bug that could show the due date and gestational age one day early for users in time zones west of UTC, including the Americas. |
| 13 Oct 2026 | Creatinine clearance calculator | Added ideal and adjusted body weight results, because the choice of weight in obese patients changes the estimate more than any other input. |
| 12 Oct 2026 | Clinical unit converter | When the four converter pages were merged, the hypothermia stages were corrected to the standard mild, moderate and severe bands, and the low blood glucose bands to the ADA level 1 and level 2 definitions. |
There are no accounts. Calculators run in your browser and nothing you type into them is sent to us. The practice hub keeps your progress in your own browser’s storage, so it stays on that device and disappears if you clear it; the hub has an export code if you want to move it. The site uses Google Analytics to count visits. Details are in the privacy policy.
NursingCalc is free and will stay free. Running costs may be covered by advertising. Advertisers have no say in which formulas are used, what a calculator outputs or what a reference page says, and nothing on the site is paid placement. If that ever changes for a specific item, it will be labelled.
An independent publisher. NursingCalc is not part of a hospital, university or nursing school, and its pages are not signed off by named clinicians. Instead, every formula and range cites the published source it comes from so that anyone can check it.
Each calculator implements a standard published formula, names its source on the page, and is tested against worked examples, including unit conversions and edge cases. Results should still be checked against your facility’s protocols and, for high-alert drugs, by an independent second person.
Email info@nursingcalc.com with the page address and what you think is wrong. Clinical errors are checked against the primary source first, and substantive corrections are listed in the corrections log on this page.
No. Calculators run in your browser and nothing you type is sent to the site. Practice progress is saved only in your own browser’s storage on that device.