EMS Medical Calculators
4 free tools built for EMT, AEMT, and paramedic students — covering the medical math and clinical reference tables most commonly tested on the NREMT. Start with the Medication Dosage Calculator for D/H × V practice, then use the IV Drip Rate Calculator for flow rate and drip problems.
IV Drip Rate Calculator
Calculate drops per minute (gtt/min) for manual gravity IV infusions, or mL/hr for electronic pump settings. Includes all drop factors and a manual formula reference.
Inputs
- • Volume to infuse (mL)
- • Time (minutes or hours)
- • Drop factor (gtt/mL)
Outputs
- • Drip rate (gtt/min)
- • Flow rate (mL/hr)
- • Drop factor conversions
Medication Dosage Calculator
Calculate the volume to administer using the D/H × V formula or concentration method. Includes common EMS drug presets (epinephrine, naloxone, dextrose) and a concentration reference table.
Inputs
- • Desired dose
- • Dose on hand
- • Volume on hand — or — concentration (mg/mL)
Outputs
- • Volume to administer (mL)
- • Sanity check
- • Calculation shown
Weight-Based Dose Calculator
Calculate mg/kg bolus doses and mcg/kg/min infusion rates with automatic lbs-to-kg conversion. Covers bolus drugs (adenosine, epi, amiodarone) and vasopressor drips (dopamine, epi infusion).
Inputs
- • Patient weight (lbs or kg)
- • Dose in mg/kg
- • Concentration (mg/mL or mcg/mL)
Outputs
- • Total dose (mg or g)
- • Volume to draw (mL)
- • Pump rate (mL/hr) for drips
Pediatric EMS Reference
Enter age to get estimated weight, minimum systolic BP, normal vital sign ranges, and estimated drug doses. Includes the full Broselow color zone reference table.
Inputs
- • Patient age (years + months)
Outputs
- • Estimated weight (kg)
- • Minimum systolic BP
- • Normal vital signs
- • Estimated drug doses
EMS Math Formula Reference
These are the seven formulas most commonly tested on NREMT-style questions. The NREMT cognitive exam does not allow calculators — you need to be able to apply each formula on scratch paper under time pressure. Write these out by hand daily until recall is automatic.
Drip Rate
gtt/min = (Volume mL × Drop factor) ÷ Time (min)
Flow Rate
mL/hr = Volume (mL) ÷ Time (hr)
Drug Dosage (D/H×V)
Volume = (Desired ÷ Dose on Hand) × Volume on Hand
Weight Conversion
kg = lbs ÷ 2.2
Pediatric Weight
kg ≈ 2 × (age in years + 4)
Min Pediatric SBP
SBP min = 70 + (2 × age in years)
mcg/kg/min Drip
mL/hr = (mcg/kg/min × kg × 60) ÷ Conc (mcg/mL)
How to Use These Calculators for NREMT Prep
The most effective study strategy is to solve problems manually first, then use these calculators to check your work. Working through the formula on paper builds the deep understanding that exam questions require — even when the numbers are changed or the problem is framed differently.
- Start with the formula. Before entering numbers into any calculator, write out the formula by hand and identify which values go where.
- Solve manually on scratch paper. Work through the calculation using basic arithmetic. Show your units at each step to catch errors.
- Verify with the calculator. Enter your inputs and compare your manual answer to the calculator result. If they match, your process is correct. If they don't, re-examine your formula application.
- Practice the presets. Each calculator includes real EMS drug scenarios. Use the preset buttons to work through common drugs (epinephrine, naloxone, adenosine, dopamine) until the math feels automatic.
- Apply the pediatric reference. Pediatric scenarios add the weight estimation step. Practice combining weight estimation + dosage calculation in two-step problems.
EMS Medication Math: The Complete Guide
EMS medication math covers three core skill areas, each with its own formula structure. Understanding all three — and when each applies — is essential for the NREMT and for safe patient care in the field.
1. Single-Dose Medication Calculations
The D/H × V formula answers: "How much do I draw up?" You need three numbers: the dose ordered (Desired), the dose in the vial (Have), and the volume of fluid that contains the Have dose (Volume). This applies to nearly every prefilled syringe or vial-based EMS medication.
Epinephrine 0.3 mg IM
1:1,000 (1 mg/mL)
(0.3 ÷ 1) × 1 = 0.3 mL
Naloxone 0.4 mg
0.4 mg/mL vial
(0.4 ÷ 0.4) × 1 = 1.0 mL
Dextrose 50% 25 g
500 mg/mL (0.5 g/mL)
(25 ÷ 0.5) = 50 mL
2. IV Drip Rate and Flow Rate Calculations
IV math appears in two forms: setting a gravity drip (gtt/min) or programming an electronic pump (mL/hr). The drip rate formula adds the drop factor — a property of the IV tubing, printed on the package, that determines how many drops equal 1 mL.
| Scenario | Formula |
|---|---|
| 1 L NS over 8 hr, 15 gtt/mL tubing | (1000 × 15) ÷ 480 |
| 500 mL LR over 4 hr (pump setting) | 500 ÷ 4 |
| 250 mL over 2 hr, 10 gtt/mL | (250 × 10) ÷ 120 |
| KVO (keep vein open) microdrip | (30 × 60) ÷ 60 |
3. Weight-Based Dosing
Pediatric and advanced-level medications are often dosed per kilogram. The two most common forms are one-time bolus doses (mg/kg) and continuous infusion rates (mcg/kg/min). The critical first step for both is converting the patient's weight from pounds to kilograms.
Bolus Dose (mg/kg)
Adenosine 0.1 mg/kg for a 22 kg child:
0.1 × 22 = 2.2 mg total
2.2 ÷ 3 mg/mL = 0.73 mL
Infusion (mcg/kg/min)
Dopamine 5 mcg/kg/min, 70 kg patient, 1,600 mcg/mL:
(5 × 70 × 60) ÷ 1600
= 21,000 ÷ 1600 = 13.1 mL/hr
Frequently Asked Questions
Which calculator should I start with?
Start with the Medication Dosage Calculator — the D/H × V formula is the most frequently tested EMS math skill and the foundation for all drug administration. Once that formula is automatic, add IV drip rate practice, then weight-based dosing.
Are calculators allowed on the NREMT?
No. The NREMT cognitive exam does not permit calculators. Use these tools to verify your manual calculations during study — not as a shortcut. The goal is to internalize the formulas so thoroughly that you can execute them on scratch paper in under 60 seconds.
How precise do I need to be on EMS math questions?
NREMT questions typically present answer choices that are far enough apart that correct formula application — with basic rounding — leads to the right answer. Focus on using the correct formula and correct units. Practice rounding to the nearest whole number for gtt/min and to one decimal place for mL.
What's the most common EMS math mistake on exams?
Unit mismatch is the #1 error: using minutes when the formula requires hours (or vice versa), or mixing mg and mcg without converting. Always write your units at every step. If the units don't cancel correctly, the formula is wrong.
More Health & Wellness Calculators
Beyond EMS math, explore our body and health calculator suite: