Free printable
EMS formula sheet.
Every calculation you need for class, clinicals, and the exam — each one with a worked example so you can check your math.
IV & drip calculations
Drops per minute (gtt/min)
(Volume in mL × drop set gtt/mL) ÷ time in minutes
Example: 500 mL over 60 min with a 10 gtt set = (500 × 10) ÷ 60 = 83 gtt/min
mL per hour
Total volume ÷ total hours
Example: 1,000 mL over 8 h = 125 mL/h
Concentration (mg/mL)
Total mg in bag ÷ total mL in bag
Example: 400 mg dopamine in 250 mL = 1.6 mg/mL = 1,600 mcg/mL
Weight-based infusion (mcg/kg/min → mL/h)
(dose mcg/kg/min × kg × 60) ÷ concentration mcg/mL
Example: 5 mcg/kg/min, 80 kg, 1,600 mcg/mL = (5 × 80 × 60) ÷ 1,600 = 15 mL/h
Dose calculations
Volume to administer
(Desired dose ÷ concentration on hand) = mL to give
Example: Need 50 mg of a 100 mg/2 mL vial → 50 ÷ 50 mg/mL = 1 mL
Weight-based dose
Dose per kg × patient weight in kg
Example: Fentanyl 1 mcg/kg for 70 kg = 70 mcg
Pounds to kilograms
lb ÷ 2.2
Example: 185 lb ÷ 2.2 = 84 kg
Percent solution
x% = x grams per 100 mL
Example: D50 = 50 g per 100 mL = 25 g in a 50 mL prefill
Assessment & hemodynamics
Mean arterial pressure (MAP)
(SBP + 2 × DBP) ÷ 3
Example: 110/70 → (110 + 140) ÷ 3 = 83 mmHg
Shock index
Heart rate ÷ systolic BP
Example: HR 120, SBP 90 → 1.33 (≥ 0.9 suggests occult shock)
Pulse pressure
SBP − DBP
Example: 120/80 → 40 mmHg (narrowing suggests tamponade/shock)
Cerebral perfusion pressure
MAP − ICP
Example: MAP 85, ICP 20 → 65 mmHg (goal ≥ 60)
Pediatric & burns
Pediatric weight estimate
(2 × age in years) + 8 = kg
Example: 6-year-old ≈ 20 kg
Pediatric minimum SBP
70 + (2 × age in years)
Example: 4-year-old → 78 mmHg minimum acceptable SBP
ETT size & depth (uncuffed)
Size = (age ÷ 4) + 4; depth = tube size × 3
Example: 8-year-old → 6.0 tube, insert to ~18 cm
Parkland formula
4 mL × kg × %TBSA of LR over 24 h (half in first 8 h)
Example: 80 kg, 20% TBSA = 6,400 mL; 3,200 mL in first 8 h = 400 mL/h
For exam preparation only. Confirm all doses and concentrations against your local protocol.
Run the numbers automatically
Use the calculators, then practice the math under time pressure.