Weight-Based Dosing Calculator for Nurses
Weight-based dosing with unit guards and safety validation. Prevents common calculation errors.
Common clinical questions about this calculator and its applications
Should I use actual body weight or ideal body weight?
This depends on the specific medication and patient population. For most medications in adults, use actual body weight unless the drug is lipophilic (fat-soluble) or the patient is obese (BMI >30). For obese patients, some medications require adjusted body weight or ideal body weight calculations. Always consult drug-specific guidelines or your pharmacist.
What if the calculated dose doesn't match standard preparations?
Round to a practical dose based on available concentrations and administration volumes. For example, if calculated dose is 487 mg but your vials are 500 mg, rounding to 500 mg is usually acceptable for most medications (within 10-15% is typically safe). Always verify with your facility's rounding protocols and consider the medication's therapeutic index.
How do I handle pediatric dosing?
Pediatric dosing is more weight-dependent and less forgiving of errors. Always double-check calculations, use the child's most recent weight, verify maximum doses don't exceed adult doses, and have another nurse independently verify high-alert medications. Many pediatric doses have strict mg/kg/day maximums.
What's the difference between mg/kg/dose and mg/kg/day?
mg/kg/dose is the amount per single administration, while mg/kg/day is the total daily dose divided across all administrations. For example, a medication ordered as '10 mg/kg/day divided Q8H' means the daily dose is 10 mg/kg, but each individual dose is 10÷3 = 3.33 mg/kg per dose.
When should volume per dose trigger concern?
Volumes >30 mL for IM injections are generally impractical and painful. For IV administration, volumes >50 mL for a single push/bolus may be excessive depending on the medication. Very large volumes may indicate a concentration error or need for different administration route. Always consider patient's fluid status and age.
About Our Validation & Sources
All calculators on Nurside use evidence-based formulas from standard clinical practice guidelines. Our validation thresholds are derived from clinical experience, published literature, and expert consultation.
Safety Features: Built-in validation catches common entry errors (like unit confusion), flags unusually high or low values, and requires explicit confirmation for potentially dangerous calculations. This is designed to support, not replace, your clinical judgment.
Formula Transparency: Click "Methods Used" in any calculator to see the exact formula and safety thresholds being applied. We believe you should always understand how your clinical tools work.
Educational Purposes Only: These calculators are provided for educational and clinical support purposes. They do not constitute medical advice and should not replace independent clinical judgment. Always verify calculations against your facility's protocols and the patient's specific clinical context.