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Nursing calculation guides
One guide for each NurseTools tool: the formula or scale with its units, a worked example with made-up numbers, the common pitfalls and the sources behind it. Each guide also says plainly whether the tool is planned for launch or still in clinical review.
- Vitals
How to Calculate BMI: Formula, Units and a Worked Example
BMI is weight in kilograms divided by height in meters squared. See the metric and U.S. formulas, adult categories, a worked example and common limits.
- Vitals
How to Calculate Mean Arterial Pressure (MAP) From BP
MAP is estimated as one third systolic plus two thirds diastolic. See both forms of the formula, a worked example, and why it is only an estimate.
- Medication
Drug Dosage Calculation Basics: Desired Over Have and mg/kg
A plain-language guide to dosage math taught in nursing school: desired over have, weight-based mg/kg, unit conversion, rounding and ISMP zero rules.
- Medication
IV Flow Rate and Drip Rate Calculations Explained
The two IV math formulas: mL per hour = volume / time, and drops per minute = volume x drop factor / minutes, with a step-by-step practice example.
- Maternal
How to Calculate a Due Date (EDD) and Gestational Age
Learn Naegele's rule step by step: add 280 days to the last menstrual period, count gestational age in weeks and days, and see when ultrasound redates.
- Maternal
Apgar Score Explained: The Five Criteria, Scoring and an Example
The Apgar score rates a newborn on five signs, 0 to 2 points each, at 1 and 5 minutes after birth. See the table, a worked example and its limits.
- Emergency
Parkland Burn Formula: How the Fluid Calculation Works
How the Parkland formula estimates 24-hour burn fluids: 4 mL x kg x %TBSA, half in the first 8 hours from the burn, with a step-by-step practice example.
- Neurology
Glasgow Coma Scale (GCS): Scoring, Components and a Worked Example
The Glasgow Coma Scale adds eye (1 to 4), verbal (1 to 5) and motor (1 to 6) scores for a total of 3 to 15. See the components, NT and a worked example.
- Labs
How to Read an ABG: A Step-by-Step Guide for Nurses
Learn a simple step-by-step way to read an arterial blood gas: check pH, find the cause, look at compensation, and work through one made-up example.
- Labs
Normal Lab Values for Nurses: Units and Reference Ranges
What reference intervals are, why they vary by lab, how conventional and SI units differ, and common adult values with a unit conversion example.
- Labs
eGFR and Creatinine Clearance: CKD-EPI vs Cockcroft-Gault
How eGFR (CKD-EPI 2021) and Cockcroft-Gault creatinine clearance differ, what units they use, how CKD stages map to eGFR, and a hand-worked example.
- References
How Nurses Can Judge a Clinical Reference: A Checklist
A checklist for nurses to judge a clinical reference: who runs it, who pays, where the facts come from and how current it is, with an example.