Opioids Dosage Conversion vs Vetcalculators
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Opioids Dosage Conversion
This app is a calculator for trained medical professionals to convert opioid analgesic dosages. It supports various common opioids and administration routes, offering features like breakthrough dosing and cross-tolerance calculations.
- Opioid dosage conversion
- Multiple drug support
- Multiple route support
- Breakthrough dosing calculator
- Incomplete cross tolerance option
- Instructional details
Read full descriptionHide full description
Opioids by Chris Marcellino MD and Norris Vivatrat MD is an opioid analgesic dosage conversion calculator for use by trained medical professionals. The application supports conversion to and from opioids commonly prescribed and used in U.S. hospitals orally, parenterally, or transdermally, including morphine, codeine, hydromorphone, hydrocodone, fentanyl, methadone, oxycodone and oxymorphone. The application is intended to help and instruct in the process of conversion of opioid regimens. • Native support for iPhone, iPad and iPod touch • Multiple route support • Multiple drug support • Incomplete cross tolerance option • Breakthrough dosing calculator • Provides instructional details about each calculation • Saves last calculation on exit • Supports landscape and portrait modes • Reference guide By Professor EBM, the Internal Medicine Residency Teaching Resource for Evidence-Based Medicine: http://www.professorebm.com/, a resource of the Santa Clara Valley Medical Center. While effort has been made to ensure that calculations are accurate and that conversion factors are in accordance with current accepted medical practices, use of this application is entirely at your own risk. This application should only be used by trained medical professionals and all results should be double checked by hand. Use of the app requires acceptance of the terms of use that are included with the application. Please send support requests and feedback using the link in the About tab of the app, though as a free academic tool we only have limited resources to address new feature requests. Opioid equipotency data is taken from CAPC conversion values except where noted (see the reference tab in the app.) CAPC values are as published in the Center to Advance Palliative Care Prescribing Opioids: A Reference Guide curriculum, which are adapted from McPherson ML. Demystifying Opioid Conversion Calculations: A Guide for Effective Dosing, 2nd ed. American Society of Health-System Pharmacists, Bethesda, Maryland, 2018. EPEC values are as published in EPEC-O Participants Handbook, 2005. Chris Marcellino, MD — Mayo Clinic Norris Vivatrat, MD — UCSD Medical Center Special thanks to Dr. Tom Mouser (EveryStep, Des Moines, IA) and Dr. David Rand (UVM Medical Center).
Vetcalculators
This app provides veterinarians and staff with a comprehensive suite of calculators for drug dosages, medical measurements, and patient assessments. It also includes a wide range of veterinary references for quick access to essential information.
- Drug dose calculators
- Emergency drug dosages
- Fluid therapy rates
- Toxicity calculators
- Pet age calculator
- Veterinary references
- Unit conversion
Read full descriptionHide full description
The Ultimate Veterinary Calculator App Vetcalculators is a Monthly Subscription. First Month is Free Vetcalculators is the number one Veterinary Calculator App for veterinarians, veterinary technicians, and staff. With Vetcalculators, one can quickly and easily calculate a variety of veterinary dosages and measurements. Vetcalculators includes calculators for: • Popup Drug Dose Calculator with ~200 veterinary drugs included • Emergency Drug dosage calculator • Anesthetic, Antibiotic and General drug dosage calculators • CRI (constant rate infusions) calculators • Fluid therapy rates • Blood glucose curve generator • Canine and Feline Calorie calculator • Pain score calculators • Chocolate toxicity • Rodenticide toxicity • Xylitol toxicity • Poisonous Plants • Blood transfusion volumes • Pet age and pregnancy calculator • Blood pressure • Trauma Triage scores • Modified Glasgow Coma score • Cushing diagnostic score • Unit conversion Vetcalculators also includes a variety of veterinary references, including: • Drug labels • IRIS stages • Pain scales • Normal lab values • Heartworm treatment protocols • Lab test protocols • Microchip lookup • Vertebral heart score • Body condition score charts • ACVIM Mitral Valve Disease 2019 Consensus Guidelines • ACVIM Feline Cardiomyopathy 2020 Consensus Guidelines • Dental charts • Feline and Canine AAHA Vaccination Guidelines • Flea and tick product information • Dog and cat breed search • RECOVER Guidelines • Document and QR code scanning Designed for Veterinarians by a Veterinarian, Vetcalculators is a valuable resource for all veterinarians, veterinary technicians, nurses, and staff. It can be used to calculate a variety of veterinary drug dosages, medical calculations, and measurements quickly and easily. The app also includes a variety of veterinary medical references. Download Vetcalculators today and start providing the best possible care for your patients! Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is in-app purchases: Opioids Dosage Conversion at none against Vetcalculators's 1. Opioids Dosage Conversion also leads on review sentiment (78% vs 45%). Vetcalculators's advantage is rating (4.7 vs 4.3) and ratings volume (606 vs 18). On price, update cadence, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Vetcalculators sells 1 in-app purchase, starting at $3.99 per month. Opioids Dosage Conversion asks for nothing beyond the download.
Vetcalculators holds the better App Store score, 4.7 against 4.3. That said, the two scores are not equally well evidenced: Vetcalculators has 606 ratings behind it against 18, so its average is the more settled of the two. Written reviews complicate that: 78% of Opioids Dosage Conversion's written reviews are positive against 45% of Vetcalculators's, so the app with the better star average is not the one people write more warmly about.
Opioids Dosage Conversion ships an update every 4 months, Vetcalculators every 3 months. The most recent releases landed on September 17, 2026 and September 22, 2026 respectively.
| Parameter | Opioids Dosage Conversion | Vetcalculators |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (18 ratings) | 4.7 (606 ratings) — better |
| Positive reviews | 77.8% of reviews — better | 45.2% of reviews |
| Number of ratings | 18 | 606 — better |
| Update frequency | Every 4 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Subscription |
| Best chart rank | — | #41 — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 15.6 |
| Further details — not scored | ||
| Size | 2 MB | 85 MB |
| Age rating | 17+ | 17+ |
| Developer | Chris Marcellino MD LLC | LifeLearn USA |
Customer experience
Opioids Dosage Conversion
Vetcalculators
Bugs and requests
Opioids Dosage Conversion
Not enough reviews yet to summarise bugs or requests.
Vetcalculators
Reported bugs
8 issues- App crashes or closes immediately upon opening
- UI elements unresponsive to clicks and taps
- Drug database fails to load after updates
- Data not persisting when app order is changed
- New drugs and concentrations not saving properly
Show 3 moreShow fewer
- Subscription charges reappearing after app reinstallation
- Recurring charges despite cancellation
- Inconsistent functionality across different sessions
Requested features
8 requests- Support for additional animal species beyond dogs and cats
- Gram weight unit option in addition to lbs and kgs
- Cross-device data synchronization
- Offline functionality without internet requirement
- Student pricing or free tier option
Show 3 moreShow fewer
- Ability to highlight/select individual drug line items
- Improved drug order saving functionality
- Free or freemium version with basic features
In-app purchases
Opioids Dosage Conversion
No in-app purchases
Vetcalculators
- Vetcalculators Subscription1 Month trial$3.991 Month
Questions
Is Opioids Dosage Conversion free?
Is Vetcalculators free?
Which has better reviews, Opioids Dosage Conversion or Vetcalculators?
Do Opioids Dosage Conversion or Vetcalculators have ads?
Which is updated more often, Opioids Dosage Conversion or Vetcalculators?
Other comparisons















