Medical Metrics Made Easy: A Guide to 23 Free Medical Calculators

This post unveils a robust collection of 23 free and open-source medical calculators, vital game-changers in the medical field for professionals and patients alike. These tools revolutionize health metrics calculation, providing lightning-fast and precise results, thus supercharging the efficiency of diagnoses and treatment plans.

For patients, these calculators are an empowering tool, providing an effortless way to stay on top of their health metrics and achieve a deeper comprehension of their health status.

The open-source design of these tools is a boon, paving the way for relentless enhancements and adaptations to cater to the ever-evolving needs of the medical community. They stand as indispensable, dynamic resources, propelling proactive health management and enhancing the understanding of medical metrics.

1. Heval (Medical calculator for intensive care unit)

Heval is a medical calculator specifically designed for use in intensive care units. Despite its self-deprecating description of being "ugly as hell," it provides an array of useful features that help healthcare professionals evaluate their patients' needs efficiently.

The tool requires minimal user input and estimates unknown values automatically whenever possible, such as weight based on height. It focuses on measurable parameters, eliminating the need for direct patient interaction. The app doesn't have a "Calculate" button, as it instantaneously updates evaluated data as soon as you input new information.

Heval is more than just a calculator. It interprets arterial blood gases (ABG), uncovers hidden processes, and provides recommendations for immediate correction measures and infusion therapy.

The app is transparent about its calculations. Each calculation is referenced and explained in the source code, allowing anyone to reproduce it. Plus, it's infused with electrolytes, making it an engaging tool for medical professionals.

The app is written with Python and it is released under the GPL-3.o license.

2. BMI Calculator

BMI Calculator is a Windows application designed primarily to assist individuals with weight issues, but it can also be beneficial for anyone interested in understanding their health status. It computes a person's Body Mass Index (BMI) and their ideal weight. This application is particularly useful in the Healthcare Industry.

The user interface is built with Java Swing and the application itself is programmed in Java, placing it under the category of Medical Science Apps. Moreover, the application is hosted on OnWorks, allowing it to be run online easily from any free operating system provided by OnWorks.

To use this application, it needs to be downloaded to your PC and uploaded to the OnWorks file manager. It can then be run on any OnWorks online emulator, ideally the Windows online emulator. For Linux users, the app can be run using Wine, an open-source Windows compatibility layer that allows Windows programs to run directly on any Linux desktop without actually needing Windows.

3. health-calculator (TDEE Calc)

The health-calculator is a useful JavaScript library designed for calculating well-known health-related metrics. It can be easily installed via npm using the command npm i health-calculator.

JavaScript developers can easily install it using npm i health-calculator.

For usage, you can import it in your JavaScript file and use its functions. For example, hc.dietary.tdee('male', 20, 80, 180, 'moderate') is a function to calculate the Total Daily Energy Expenditure (TDEE). The health-calculator library is divided into several modules, such as body_measurement, dietary, sports, and util, each dedicated to a specific area of health metrics.

4. OpenMedCalc (API)

OpenMedCalc is an open-source API designed for calculating common medical formulas. Built using FastAPI, adhering to the OpenAPI specification, it can easily integrate into various applications, including OpenAI's GPT functionality. Its primary purpose is educational and not intended for patient care.

OpenMedCalc offers interactive live API documentation through Redoc and Swagger UI. It includes the capability to calculate several critical formulas used in medical fields, such as MELD, MELD-Na, Caprini VTE, Wells DVT score, and PSI/PORT.

The use-cases for this API are broad, particularly in the educational realm. For instance, it can enhance medical training applications by providing accurate calculations for various medical formulas. Additionally, it can be integrated into medical research applications where such formulas are frequently needed. It could also be a valuable tool for health-tech startups building innovative medical applications, enabling them to focus more on their core features and less on developing proprietary medical calculation algorithms.

5. Simple Calculators In Medicine & Critical Care

The "Simple Calculators" project is a specialized suite of calculators created for use in the realms of medicine and critical care. Available in both Spanish and English, the project aims to offer essential tools that save time for healthcare professionals, particularly in the fields of Anesthesia & Critical Care.

A key feature of the project is a mini calculator for Parenteral Nutrition in critically ill adults. This calculator aids in precise and individualized nutrition calculations, providing a critical tool for patient care. Another component, the Pediatric Fluidotherapy section, includes a calculator for administering fluids and drugs for children in the operating room. This section is still under development, signaling the project's ongoing commitment to expanding its capabilities.

A standout feature of the project is the Opioid Calculator. This tool assists in determining opioid equivalence, rotation, and tapering, which are all vital aspects of pain management and efforts to reduce opioid dependency.

The project is spearheaded by Aurora Baluja González, a member of the Anesthesiology and Resuscitation Service at the University Hospital in Santiago de Compostela, Spain. Her work emphasizes the practical application of medical calculations in everyday healthcare scenarios, demonstrating the real-world impact of the "Simple Calculators" project.

6. Clinical Calculator API

The Clinical Calculator API is a Ruby on Rails application that offers a variety of clinical calculations through a REST API. It is currently a work in progress and is open-source, but it is not intended for live use in clinical systems with actual patients. The API aims to avoid the need for local implementation of calculations in applications, which could lead to errors. Instead, it allows calculations to be openly peer-reviewed, clinically assured, and verifiable. It also simplifies the process of MHRA registration for medical devices, as it needs to be done only once at the API level.

The API serves as a shared knowledge base to which clinicians can contribute. It's designed to facilitate decision-making by medical professionals who typically use clinical calculations as tools. Despite the availability of many such tools on websites like MDCalc, they aren't readily usable by computer programs. This API fills that gap by providing a structured data 'question and answer' format that computers can use.

It has been observed that some of the calculations required by doctors aren't readily available in currently used GP clinical systems, and this API strives to address this deficiency. One such absent calculation is the calculation of Height, Weight, and BMI Centiles, critical for managing a variety of childhood conditions, including obesity.

The API's implementation involves each calculation being a single Rails controller with a 'calculate' action containing the calculation code. Some calculations use an external library, such as an open-source C implementation of the calculation.

It currently offers endpoints for calculations like Body Mass Index (BMI), Body Surface Area (BSA), CHADS2VASC2 Clinical Stroke risk score, and Wells' Deep Venous Thrombosis clinical risk score, among others.

7. ASCVD Risk App

The ASCVD Risk App is a web-based application designed to estimate the risk of atherosclerotic cardiovascular disease (ASCVD) for its users. The tool is built on technologies such as React, ES2015, SMART, and FHIR, making it a robust and cutting-edge platform.

The application offers an estimate of 10-year and lifetime ASCVD risks based on the 2013 ACC/AHA Guidelines and uses the Pooled Cohort Equations and lifetime risk prediction tools. Furthermore, it provides a simulation of potential risk reduction based on various risk factors, enabling users to see the potential impact of lifestyle changes on their ASCVD risk.

The app is designed for users with an assumed LDL - Cholesterol level of less than 190 mg/dL. It takes into account various factors including sex, age, race, total cholesterol, HDL - Cholesterol, systolic blood pressure, diabetes status, current smoking status, and hypertension treatment status.

While the tool provides valuable insights, it doesn't replace professional medical advice. Its 10-year risk estimate is primarily applicable to African-American and non-Hispanic white men and women aged 40 to 79, while the lifetime risk estimate is primarily applicable to non-Hispanic white men and women aged 20 to 59. For other ethnic groups, the risk may be overestimated or underestimated.

8. Watoto

Watoto is an interactive medical calculator designed to implement Kenyan basic pediatric protocols. It is designed for trained medical staff and aims to support Kenyan clinicians to assess the nutritional status of patients, approximate certain anatomical attributes, and calculate essential drug dosing for pediatric patients. The goal of the app is to simplify these processes and reduce the likelihood of human error.

The app is available for Android devices via the Google Play Store. The iOS version is currently facing review issues with Apple. Watoto's source code is openly published on GitHub, promoting transparency and inviting contributions from the broader community.

This project is built on top of Facebook's React-Native framework, designed with a common code base for both Android and iOS platforms. NPM is used as the package manager, as well as to run the setup and testing.

Watoto was developed in Kenya through a collaborative effort between UK volunteers and local doctors. This was a project of the RCPCH1 Global Links program in partnership with the KPA2. The developers express their gratitude towards THET and UK Aid.

Currently, you can install and run the app from source, as it is not available at any Android or iOS store anymore. It is also important to note that it is did not receive any update for years.

9. BMI Calculator (for React Apps)

The BMI Calculator is a React Hooks application that calculates a person's BMI and can store data for up to 7 days using LocalStorage.

10. BMI Calculator with flutter

This is an open-source BMI calculator that is written in Flutter.

11- SuperCalculator

Super Calculator is a comprehensive web-based, self-hosted application that offers an extensive array of 21 calculators. Developed using pure Javascript without any framework or library, this tool features diverse calculators specifically designed for Mathematics, Financial calculations, Graphing, Conversion, as well as a Password and QR Generator. It also includes miscellaneous calculators for various other tasks.

Notably, the Super Calculator also provides some medical calculators and tools, broadening its functionality and making it a versatile tool for a wide range of users.

This project is particularly beneficial for beginners interested in learning Javascript projects without any frameworks or libraries, thanks to its straightforward logic and minimal lines of code.

The application's homepage stacks all 21 calculators on a single page, providing links to the individual pages of each calculator. This page is fully responsive and serves as the main index.html page. Overall, the Super Calculator stands out as a user-friendly, comprehensive, and practical tool for any calculation needs.

It includes a BMI calculator and a responsive result BMi table

12- BMI Calclator

The BMI (Body Mass Index) Calculator JavaScript is a versatile and user-friendly tool that enables individuals to calculate their BMI on any device, including mobiles, computers, and desktops. The developer of this application created it because they noticed a lack of satisfactory BMI calculators available online.

This tool is accessible via a web link and also as a mobile app on the Google Play Store. Users are encouraged to utilize this calculator for their BMI calculations and are invited to report any errors or suggestions directly on GitHub.

This open invitation not only ensures the calculator's accuracy but also fosters a sense of community and continuous improvement.

13- 🔖BMI Calculator

The "BMI Calculator" is a fantastic Android app that makes it easy to monitor your Body Mass Index (BMI). It's an accessible and user-friendly tool, compatible with Android devices, which allows users to calculate their BMI quickly and accurately. If you have any suggestions or find any errors, the developer encourages you to reach out to them on GitHub or submit your modifications, fostering a sense of community and continuous improvement.

The app is built with an array of high-quality tools, including Kotlin, the official programming language for Android development, and other customizable Android UI libraries like HorizontalPicker and WheelView. It also features a 'swipe-button', a highly customizable button, enhancing the user experience.

The app even incorporates Material Components for Android, ensuring a modern and attractive design. As a testament to its focus on design, the app also has a presence on Dribbble, a platform for digital designers. Overall, the "BMI Calculator" stands out as a valuable, easy-to-use, and well-designed tool for anyone wishing to track their health metrics on an Android device.

14- BMI Calculator Widget for WordPress

The "BMI Calculator Widget for WordPress" is a highly efficient and free Body Mass Index (BMI) calculator that provides invaluable health insights to both children and adults. This powerful tool is designed to compute and categorize BMI metrics using reliable data from reputable health organizations such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC).

This widget is the perfect integration for any WordPress-based website that promotes health consciousness and wellness. Its simplicity and intuitive design make it an effective tool for users who want to keep a regular check on their BMI and overall health status.

It offers an easy-to-understand interface that allows users to input their weight and height details, from which the calculator promptly computes the BMI metrics and provides a classification. This classification is based on internationally recognized health standards, providing users with a reliable assessment of their health status.

What makes the "BMI Calculator Widget for WordPress" even more appealing is its ease of installation. As a WordPress extension or plugin, it seamlessly integrates with your WordPress website without requiring any complex coding or technical expertise.

To install this widget, you only need to navigate to the WordPress plugin directory, search for the "BMI Calculator Widget," and click on the 'Install' button. Once installed, it can be easily added to any part of your website using the widget feature in the WordPress dashboard. The result is a fully functional, easy-to-use BMI calculator that enhances your website's value by providing a critical health measurement tool to your users.

The "BMI Calculator Widget for WordPress" is more than just a calculator; it's a valuable health monitoring tool integrated seamlessly into your website, enhancing its usability and value to users. Its easy installation and user-friendly interface make it a fantastic addition to any health-conscious WordPress site.

15. Calorie Calculator

The "Calorie Calculator" is an Android application that calculates key aspects of a user's health such as Basal Metabolic Rate (BMR), daily caloric intake, and Body Mass Index (BMI). By factoring in sex, height, weight, and age, it accurately computes the BMR, which is then used to calculate the daily caloric intake needed to maintain weight. The app also calculates the user's BMI, a critical metric in determining overall health.

What sets the app apart is its ability to save each entry under the user's name. This feature allows users to view all entries or filter to view only the 'healthy' entries - those with BMIs between 18.4 and 24.9. Additionally, the app provides a unique feature that allows users to view a graph for each entry. This graph displays how much a person needs to eat to maintain weight, lose 1 lb a week, or gain 1 lb a week. This comprehensive, user-friendly application is a valuable tool for anyone monitoring their health and dietary intake.

16. BMI-Calculator

The "BMI-Calculator" is a superior Java desktop application, engineered to calculate a user's Body Mass Index (BMI) with absolute accuracy. This crucial health metric, derived from a person's weight and height, is in good hands with our application. We have harnessed the power of Java Swing, a premier widget toolkit for Java, to deliver a remarkable and highly responsive user interface.

By leveraging Java as our primary programming language, we guarantee robust and unwavering performance. The state-of-the-art development tools at our disposal include the Java SDK, offering an all-encompassing set of development apparatus, and the NetBeans IDE, a time-honored integrated development environment that aids in proficient coding, seamless debugging, and meticulous testing. The BMI-Calculator stands as a simple yet potent tool for health-conscious individuals to accurately monitor their BMI.

17. Body Mass Info Table

The "Body Mass Info Table" is an intuitive application developed using PHP. The application provides a multi-weight Body Mass Index (BMI) table, which computes your BMI based on your height, age, and sex. It also calculates other crucial health metrics like Body Fat/Lean Percentage, Base Metabolic Rate (BMR), and Total Daily Energy Expenditure (TDEE) for different activity levels.

This app is designed to be user-friendly and can be installed easily, offering a quick and efficient way to keep track of your overall health.

18. Heart risk calculator

The Heart Risk Calculator is a self-hosted open-source tool designed to provide a comprehensive assessment of your heart health. It uses information gathered from various online sources to calculate potential risks related to heart health.

The calculator can help you understand your heart risk category, gain insights into normal parameters, and evaluate your risk for heart attacks, stroke disease, and more. Moreover, it can calculate your Body Mass Index (BMI) number and categorize it, helping you keep track of your overall health. The application aims to make heart risk assessment accessible and understandable for everyone.

19. Health calculator app

Calculator is an advanced, yet user-friendly, React app that effortlessly calculates your Body Mass Index, Basal Metabolic Rate, and Total Daily Energy Expenditure. It is expertly designed with react and bootstrap, and innovatively linked to a firebase database, all free of charge.

20. Calculate your heart age

The "Heart Age Calculator" is a useful web tool that aims to provide insights into your heart's health. By comparing your actual age to your 'heart age', it gives an idea of your cardiovascular health. This tool is designed for individuals aged between 30 and 95, who do not have a pre-existing cardiovascular condition.

To provide the most accurate results, the calculator requests information related to your health, such as your weight, height, blood pressure, and cholesterol levels.

However, if you don't have your blood pressure or cholesterol details, you can still use the calculator, but the results may be less precise. It also requires your age and postcode to give a more accurate heart age calculation and to help calculate your heart age based on a deprivation index. The data input is not stored or used to identify the user. The process is quick, with results typically returned in under 10 minutes.

21. Fasting Timer

"Fasting Timer" isn't just a web-based, self-hosted application, it's a comprehensive tool designed with purpose and precision. Crafted using HTML and JavaScript, it's an intermittent fasting powerhouse that actively assists users in tracking their eating and fasting periods. Its responsive nature ensures a seamless user experience across all devices.

The application boasts a timer that allows users to select a 16, 18, or 20-hour fast. A unique feature of the timer is that it saves start and end times to local storage, guaranteeing its functionality even if the user departs or refreshes the site. The timer's progress is visually displayed through an innovative circle display that updates in real-time.

Moreover, the app offers a unique feature of providing historical records of past fasts, displayed as a dynamic bar graph. This data, stored in local storage, offers insightful reflections on the user's fasting journey. It doesn't stop there, the app also includes a BMI calculator and a calorie calculator offering users pivotal insights about their health and nutrition.

The Calorie Calculator doesn't just track the user's daily calorie intake, it plans to integrate data from third-party calorie-burning trackers, making it an all-encompassing nutritional tool. These well-rounded features make the "Fasting Timer" application an indispensable ally for anyone practicing intermittent fasting.

22. Fekke's BMI calculator

Fekke's BMI calculator is an innovative and user-friendly application meticulously written in the robust programming language, C#. This handy tool is designed to aid you in accurately calculating your Body Mass Index (BMI) – a key indicator of your overall health.

By providing an easy-to-use interface, it allows you to evaluate and monitor your weight status with simplicity and convenience, potentially encouraging healthier lifestyle choices. This application proves to be an essential health management tool, designed with precision and care to help you stay on top of your health metrics.

23. Synergyfinder

SynergyFinderPlus is a software tool developed by SynergyFinder, aimed at improving anticancer treatment efficacy through the analysis of pre-clinical drug combination datasets.

It comes with an R package, which is a programming language popular in data analysis. To make it more accessible for those in the drug discovery community, SynergyFinder also offers a user-friendly web server called SynergyFinder Plus. This web platform provides a flexible and versatile interface for analyzing drug combination data, adding ease and efficiency to the process.