Reference

Calculators

24 free calculators that work on the page, each with its formula, normal range and how to read the result.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Hemodynamics

• Mean Arterial Pressure (MAP)Average pressure driving blood through the organs, worked from systolic and diastolic; the usual perfusion target in shock.

Respiratory

• Predicted Body Weight (PBW)Weight predicted from height and sex, the basis for lung-protective tidal volumes (6 mL/kg PBW in ARDS).

Renal & Electrolytes

• Urine Output (mL/kg/hr)Urine output per kg per hour, the usual way to judge kidney perfusion and stage AKI.

Fluids & Resuscitation

• Intake and Output BalanceNet fluid balance for a shift or 24 hours.
• Maintenance Fluids (4-2-1 Rule)Hourly maintenance fluid by the 4-2-1 rule from weight; a starting point, not a substitute for watching intake, output and electrolytes.

Clinical Scores

• APGAR ScoreNewborn assessment at 1 and 5 minutes after birth.
• Glasgow Coma Scale (GCS)Eye, verbal and motor responses scored 3 to 15; 8 or less usually means the airway needs protecting.

Drug Calculations

• Desired Over HaveVolume to give from the ordered dose and the dose on hand; the basic dose-to-volume check.
• Drip Rate (drops/min)Gravity-drip flow in drops per minute from volume, time and the tubing drop factor.
• mcg/kg/min to mL/hrConverts an ordered mcg/kg/min dose into the pump rate in mL/hr for a patient weight and bag concentration.
• Tablets or Capsules to GiveHow many tablets make up the ordered dose.
• Weight-Based Dose (mg/kg)Turns an ordered mg/kg dose into the total dose, and into mL when you know the concentration.

Body Metrics

• BMIWeight relative to height, a quick screen for underweight, overweight and obesity.
• BSA (Mosteller)Body surface area from height and weight; the divisor for the cardiac and stroke volume indices.

Pediatrics

• Pediatric Safe Dose RangeChecks an ordered pediatric dose against the recommended mg/kg/day range.
• Pediatric Vital Sign RangesNormal heart rate, respiratory rate and systolic blood pressure by age.

IV Therapy

• Infusion TimeHow long a bag will last at a set rate.
• IV Pump Rate (mL/hr)Sets the pump rate to infuse a volume over a given time.
• mcg/min to mL/hrPump rate for infusions ordered in mcg/min, such as nitroglycerin.
• Units/hr to mL/hr (Heparin, Insulin)Pump rate for infusions ordered in units per hour.

Conversions

• Length: Inches and CentimetersConverts between inches and centimeters.
• Temperature: °F and °CConverts between Fahrenheit and Celsius.
• Volume: Household and MetricConverts teaspoons, tablespoons, ounces and cups to milliliters.
• Weight: Pounds and KilogramsConverts between pounds and kilograms.

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Not a substitute for clinical judgment or your institution’s protocols. Not affiliated with or endorsed by any certifying body (full notice in Settings).