About MedicalEquations

MedicalEquations is a free library of medical and nursing calculators — IV drip rate, cardiac output, stroke volume, body surface area, lung volumes, dosing math, and the supporting clinical formulas behind them. No signups, no paywalls, no data collection. Just the calculations and the references they're built on.

A brief history

MedicalEquations grew out of the same family of calculator sites I built starting in the early 2000s for engineering and physics work. The medical and nursing formulas kept showing up in reader requests — students, nurses, and clinicians who wanted a quick, reliable place to compute drip rates, hemodynamic values, and body-surface-area dosing without wading through ad-heavy or login-gated pages.

The site was rebuilt on a modern static stack (Next.js) so each calculator loads quickly, works offline-friendly, and is easy to maintain. Every page now includes a worked example, a primary reference, and a last-reviewed date so you can see exactly which formula is being used and where it comes from.

How the calculators are built and verified

Every calculator is grounded in standard clinical and pharmacology references — the British National Formulary (BNF), AHFS Drug Information, established nursing pharmacology and critical-care textbooks, and peer-reviewed clinical literature. Formulas are cross-checked against these sources, worked examples are computed and independently verified, and each page cites its primary reference so you can audit the math yourself.

Medical content is sensitive. A misplaced decimal in a drug-dosing calculator or a confused unit in a hemodynamic formula can have real consequences, so reader bug reports are one of the most valuable forms of review this site gets. Nurses, pharmacists, residents, and students have caught real mistakes over the years, and I treat that feedback seriously. I'd rather fix an error than defend one — if you find one, please email me.

A note on appropriate use

These calculators are educational tools. They are not a substitute for clinical judgment, and they are not intended for direct patient-care decisions. Always verify the formula, the units, and the result against your institution's protocols, the patient's clinical context, and an authoritative drug or procedure reference before acting on any number you see here. If something looks wrong, trust your training and double-check.

About the author

Hi, I'm Jimmy Raymond. I run MedicalEquations along with a family of related engineering, finance, and reference calculator sites. My academic background is in environmental engineering and computer science — the engineering side gave me the dimensional-analysis and physics foundation, and the computer-science side gave me the tools to turn formulas into software that someone else can pick up and use in a hurry. That's an uncommon combination: most CS programs don't require classical mechanics, thermodynamics, fluid statics, or rigorous dimensional analysis, and most engineering programs don't cover the algorithms, testing methodology, and production-software practice that CS programs do. The two together are what the math verification on this site rests on.

Professionally, I spent years writing safety-critical aircraft software. That discipline shapes how the medical calculators on this site are built: each formula is pinned to a textbook or peer-reviewed clinical reference, each solver has automated tests that compare its output to known answers across the input range, and every change runs through a regression suite before it ships. None of that substitutes for clinical judgment, which is why every result page also tells you to verify against your institution's protocols before acting on a number.

I've been building and maintaining this family of sites for more than two decades because I genuinely enjoy the craft of turning a messy real-world calculation into something a stranger can use in thirty seconds and trust. I'm based in Albuquerque, New Mexico.

Contact

Email me at aj@ajdesigner.com for corrections, calculator requests, or general feedback. You can also find me on LinkedIn.

— Jimmy