CaCorrect
A single-file HTML tool for calculating and practicing albumin-adjusted (corrected) serum calcium using the Payne 1973 formula.
What This Tool Does
CaCorrect is an offline educational tool for calculating and practicing corrected calcium interpretation using the Payne 1973 albumin-adjustment formula. It is intended for healthcare students and professionals learning to interpret total calcium results in the context of abnormal serum albumin, and covers the calculation itself, its result categories, and practice against a set of scenarios.
The tool provides three modes: a calculator, a set of practice cases, and a quiz mode. In the calculator, the user enters a measured total calcium value and a serum albumin value; the tool applies the Payne 1973 formula (Corrected Ca = Measured Ca + 0.8 × [4.0 − Albumin] ) and returns the corrected value along with a classification (Hypocalcemia, Normal, or Hypercalcemia) based on an 8.5–10.5 mg/dL reference range. The Practice Cases and Quiz Mode present 25 fictional scenarios covering a range of conditions (e.g., malnutrition, chronic kidney disease, malignancy, pregnancy) for the user to work through using the same formula.
Features & Functions
- Corrected calcium calculator using the Payne 1973 albumin-adjustment formula
- Automatic classification of the corrected result as Hypocalcemia, Normal, or Hypercalcemia
- Calculation assumptions displayed alongside every result
- Unit-conversion note for calcium (mg/dL vs. mmol/L)
- "Copy Result" button that copies the corrected value, inputs, and formula reference as text
- 25 fictional practice case scenarios spanning a range of conditions and calcium/albumin combinations
- "Random Case" button that loads one practice case at a time
- "Show All Cases" button that loads all 25 practice cases at once
- Quiz Mode that presents a case and asks the user to calculate the corrected value and select its category
- Quiz progress tracking: rolling percentage correct (last 10 answers), a running "X of Y correct" count, and a streak counter
- Detection and blocking of apparent real patient identifiers entered into the calculator (e.g., SSN-like numbers, email addresses, credit-card-like numbers, medical record numbers)
- Range checks that reject calcium or albumin entries outside realistic physiological limits, with an explanatory message
- Keyboard navigation between the three modes (arrow keys)
How to Use This Tool
- Open the file in a web browser — no installation or internet connection required.
- Read and acknowledge the introductory notice to access the tool.
- On the Calculator tab, enter a measured calcium value and an albumin value, then select "Calculate" to see the corrected value, its category, and the assumptions used.
- Optionally select "Copy Result" to copy the result as text, or "Reset" to clear the fields.
- On the Practice Cases tab, select "Random Case" to work through one scenario at a time, or "Show All Cases" to view all 25 at once.
- On the Quiz Mode tab, review the case shown, enter your calculated value and select a category, then select "Submit Answer" to see feedback and updated progress.
Technical Specifications
| Format | Single HTML file |
|---|---|
| File Size | ~72 KB |
| Compatibility | Expected to work on current versions of Chrome, Firefox, Safari, and Edge |
| Internet Required | No (works 100% offline ) |
| Installation | None — open file in any browser |
| Language | English |
| Version | 1.1 |
| Last Updated | July 2026 |
| Validation | AI based Check-and-fix cycles — expert review required |
| Status | AI-generated educational prototype |
Who Should Use This
Designed For:
- Healthcare students learning to interpret calcium results in the context of abnormal albumin
- Nursing, pharmacy, and allied health professionals reviewing or practicing corrected calcium calculations
- Self-study or supplementary coursework practice
NOT Designed For:
- Clinical decision-making or patient care
- Professional certification or licensing exams
- Production use without expert validation
- Patients with CKD Stage 4–5/ESRD/dialysis, critical illness with acid-base disturbances, paraproteinemia (e.g., multiple myeloma), pregnancy, or pediatric patients — the formula is particularly unreliable in these populations
Quality & Compliance
This tool includes 14 verified features:
Your Data & Privacy:
- Works 100% offline — no internet connection needed
- No data collection — nothing is sent over the network or stored outside your current browser session
- Blocks apparent real patient identifiers from being entered (e.g., SSN-like numbers, emails, credit-card-like numbers, medical record numbers)
- Validates that entered calcium and albumin values are within realistic physiological ranges
Reliability & Compatibility:
- Expected to work on current versions of Chrome, Firefox, Safari, and Edge
- Lightweight file (~72 KB) — opens instantly
- Error messages shown directly next to the relevant input field
Sources & Transparency:
- Based on the Payne 1973 albumin-adjusted calcium formula (version and year stated in the tool)
- Formula and reference-range sources cited within the tool, including a "Current Evidence" note on more recent research questioning the formula's reliability
- Assumptions used in each calculation displayed alongside the result
- Clear unit labels throughout (mg/dL, g/dL), with a conversion note for mmol/L
Scope & Limitations:
- States the population this tool is traditionally applied to, and the populations it is particularly unreliable for
- Includes a warning that reference ranges are US-based and may vary by country/laboratory
- Shows specific examples of what NOT to use this tool for
Validation Process:
This tool was refined through AI based iterative check-and-fix cycles covering: Logic and functionality, Scientific content accuracy, Compliance and safety.
License Terms
Allowed:
- Personal educational use
- Internal training within your organization
- Academic coursework and self-study
Not Allowed:
- Production or operational use without expert validation
- Redistribution or resale (unless Commercial Resale License purchased)
- Clinical decision-making for patient care
- Removing or modifying disclaimers
Provided "as-is" for educational purposes only. All outputs must be independently verified by qualified professionals before any real-world application. This tool reflects a completed development stage and may see further refinement in future updates.
Our Fair Price Philosophy
We've enabled the 'Pay What You Want' option so you can download and evaluate the tool for free. If you find it valuable and useful to your practice, we encourage you to return and contribute a price that feels right to you and fairly reflects the value this interactive resource brings to your practice.
Your Feedback Matters
We are constantly working to improve our tools. After using CaCorrect, we would be grateful if you could share your thoughts on its functionality and usefulness.
✉️ Send Us Your FeedbackGet CaCorrect Today
(Suggested Price: $7 - $13 | Pay What's Fair)
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