MDCalc vs ClinCalc: which clinical calculator suite should your pharmacy standardize on?

Both are free. That is the first thing to establish, because most comparisons of clinical calculator suites are written as though a price difference is doing the work, and here there is none to speak of. MDCalc and ClinCalc are both free to use, and a pharmacy department choosing between them is choosing on maintenance, governance and support rather than on cost.

Which makes the decision harder rather than easier. A free tool that becomes a departmental standard is a dependency nobody signed for, and the usual purchasing controls never fire because no purchase order is ever raised. This is a comparison of what each one actually is, what is verified about each as of August 2026, and the four things worth testing before a calculator quietly becomes the number your pharmacists trust at three in the morning.

What each one actually is

MDCalc is a company. MDCalc Ltd., Inc. publishes a large library of validated clinical decision rules and scores, weighted toward risk stratification and diagnostic criteria: HEART, CHA2DS2-VASc, HAS-BLED, Wells, CIWA, PHQ-9. Its center of gravity is the emergency department and general medicine, and the content model is built around published, peer-reviewed instruments with attribution to the original authors.

ClinCalc is a pharmacist. Peter Weiss maintains ClinCalc.com and its associated apps, and the emphasis shows: pharmacokinetics, dosing arithmetic, renal function, and the kind of calculation a clinical pharmacist performs rather than the kind a triage physician performs. Its vancomycin work uses Bayesian modeling and the Sawchuk-Zaske method, which is a deeper treatment of that particular problem than a general-purpose calculator library usually offers.

So the honest first cut is that they are not really substitutes. They overlap on the common calculations and diverge on everything either one is actually known for. Departments that end up using both are not being indecisive; they are responding to a real difference in scope.

The comparison, verified August 2026

Two rows in that table matter more than the rest. The first is the enterprise row. MDCalc EHR is a distinct commercial product sold into health systems, and it carries no published price, which means the free app most clinicians know is the top of a funnel rather than the whole offering. If your evaluation is heading toward embedding calculators in the electronic health record, you are evaluating a priced enterprise product and should plan for a sales conversation, not a download.

The second is the support row, and it is the one departments consistently underweight. ClinCalc is maintained by an individual pharmacist author. That is not a criticism of the work, which is careful and well documented, and the author remains actively engaged, with ClinCalc Complete shipping a release in August 2026. It is a statement about structure: there is no vendor contract behind it, no service level, and nobody to call. A department that makes it the standard has accepted an availability and continuity risk that appears in no procurement document anywhere.

Free is a licensing status, not a risk assessment

The failure mode here is specific and worth naming. Clinical tools that cost nothing bypass every control a health system has built for software that costs something. No purchase order means no vendor security review, no business associate agreement conversation, no continuity plan and no owner. The tool then accumulates clinical dependence anyway, because pharmacists standardize on whatever is fastest and correct, and eighteen months later it is load-bearing.

The fix is not to ban free tools, which would be both unpopular and wrong, since the free options in this category are genuinely good. It is to run the same intake on them that a paid tool gets. Name an owner. Decide what happens if the site is unreachable during a night shift, and write the fallback down rather than assuming someone will improvise it. Where the tool touches anything a compliance team would care about, the vendor review belongs alongside the clinical one, and teams that already map their controls to HIPAA and SOC 2 in one place tend to catch the unowned dependency at intake instead of during an audit.

None of this applies with equal force to every calculation. A body mass index calculator failing is an inconvenience. A vancomycin or renal dosing calculation failing, or worse, silently changing behavior between versions, is a different category of problem, and the tools that carry that weight deserve the governance.

Is MDCalc free?

Yes. MDCalc Medical Calculator is free on the US App Store with no in-app purchases, and the web version is free to use. What is not free is MDCalc EHR, a separate enterprise product for embedding calculators into electronic health record workflows, and MDCalc publishes no price for it. The free consumer app and the enterprise product are different purchases with different economics.

Is ClinCalc free?

Yes for the main tools. ClinCalc.com is free on the web, and both the ClinCalc and ClinCalc Complete iOS apps are free on the US App Store. The one paid item in the family is ICU Trials by ClinCalc at $4.99, which is a reference to landmark critical care trials rather than a calculator. There is no subscription tier and no institutional license to buy.

What is the best medical calculator app for pharmacists?

For dosing arithmetic specifically, ClinCalc is the stronger of the two, because pharmacokinetics is what it was built around and it shows its working in a way a pharmacist can audit. For breadth of validated clinical decision rules across a mixed inpatient population, MDCalc has the larger and better-attributed library. Most departments that look carefully end up using both and standardizing per calculation rather than per vendor, which is a more defensible outcome than it sounds.

Does MDCalc integrate with the EHR?

Through MDCalc EHR, which is a separate commercial product rather than a feature of the free app. Pricing is not published, so an integration project starts with a sales conversation and should be budgeted as an enterprise software purchase. Departments assuming that the calculators their clinicians already use for free will simply appear inside Epic or Cerner at no cost have skipped a step.

The four tests that actually separate them

Feature lists will not decide this, because both libraries are large and both cover the common calculations. Four questions will.

Does it show the arithmetic? A result with no visible inputs cannot be checked by the second pharmacist who recalculates it on the next shift, and reproducibility between clinicians is worth more in practice than a marginally better point estimate. This is where visible-working tools earn their place, and it is why the calculators on this site report the working alongside the answer. The creatinine clearance calculator makes the weight basis an explicit selection rather than a hidden default, and the corrected calcium calculator reports how much of the result the equation added rather than measured, which for a hypoalbuminemic patient is the number that decides whether to trust it at all.

Does it tell you when not to trust it? This is the sharpest differentiator in the whole category and almost nobody tests for it. Plenty of widely used equations perform badly in specific populations. The albumin correction for calcium was never validated against ionized calcium and an international expert panel recommended in April 2026 that laboratories stop reporting it routinely. Cockcroft-Gault is being actively deprecated in favor of race-free eGFR by a National Kidney Foundation workgroup. A calculator that returns a confident number with no such caveat is not neutral; it is making an editorial choice on your behalf.

What is the update cadence, and can you see it? Both publishers ship updates, and the App Store release dates are public, which is a cheap and underused way to check that a tool you depend on is still being maintained. Do that check annually rather than at purchase, since the risk here is drift over years, not a bad decision on day one.

Who answers the phone? For MDCalc's free app, essentially nobody, and for the enterprise product, a sales and support organization. For ClinCalc, nobody by design. That may be entirely acceptable. It should be a decision recorded somewhere rather than something a department discovers during an incident.

Where a calculator stops being the answer

Both of these tools do one thing: they compute. Neither is checking whether the patient in front of you is on an interacting drug, whether the calculated dose runs into a contraindication, or whether a different agent would avoid the problem entirely. That is a separate job, and splitting it across four lookups is how it gets skipped under time pressure.

A dosing calculation is one line of a prescribing check. The ideal body weight calculator settles which kilograms go into the equation, the vancomycin AUC calculator handles the case where measured levels replace the convention entirely, and the interaction, contraindication and renal adjustment belong beside those numbers rather than after them.

For a wider view of what pharmacists are choosing between across the whole category, including the paid drug references, the comparison of drug dosing calculator apps covers seven tools with verified pricing. Departments moving from an individual habit to a departmental standard will find the contractual side in the institutional license guide.

The recommendation

Standardize per calculation, not per vendor. Use ClinCalc where the question is pharmacokinetic and the working needs to be auditable. Use MDCalc where the question is a validated clinical decision rule and attribution to the original instrument matters. Treat both as unowned dependencies until someone in the department owns them, and put the ones that carry clinical weight through the same intake a paid product would get.

The money question is a different one entirely. Neither of these tools charges you, which means neither of them is the line item to argue about. The spend in this category sits in the drug references and the EHR integrations, and that is where an evaluation deserves the time.