Math
IV rate unit-conversion exercises: drops/minute and mL/hour
Practice spreadsheet dimensional analysis with fictional infusion inputs. These exercises are not a validated dosing or pump-setting tool.
Keep volume, time, mass and concentration units explicit
This is a classroom unit-conversion exercise, not a patient-care calculator. Clinical use requires a qualified professional to verify the prescription, concentration, patient factors, device capability and local rounding/checking protocol. The fictional numbers do not recommend a drug or dose.
Volume in mL divided by hours gives mL/hour. Multiplying by the tubing drop factor and dividing by 60 gives drops/minute. For a rate already specified in micrograms/kg/minute, multiply by kg and 60, then divide by micrograms/mL. Mixing mg and micrograms introduces a factor of 1,000. Rounding here is for the exercise, not a universal device setting.
| Classroom unit-conversion calculation | Formula | Worked Example |
|---|---|---|
| Electronic Pump Rate (mL/hr) | 1,000 mL / 8 hrs | 125.0 mL/hr |
| Gravity Macrodrip (15 gtt/mL) | ROUND((1,000 * 15) / (8 * 60), 0) | 31 gtt/min (31.25 rounded) |
| Gravity Microdrip (60 gtt/mL) | ROUND((1,000 * 60) / (8 * 60), 0) | 125 gtt/min (= mL/hr!) |
| Weight-Based (5 mcg/kg/min, 80 kg, 1600 mcg/mL) | (5 * 80 * 60) / 1600 | 15.0 mL/hr |
Gravity IV drip rate in whole drops per minute (gtt/min)
A2=Volume_mL (1000), B2=Hours (8), C2=DropFactor_gtt_mL (15); rounds to whole drops because partial drops cannot be counted visually.
=IF(OR(COUNT(A2:C2)<>3,A2<0,B2<=0,C2<=0),"Invalid inputs",ROUND((A2 * C2) / (B2 * 60), 0))Weight-based unit conversion exercise
D2=Dose_mcg_kg_min (5), E2=Weight_kg (80), F2=Concentration_mcg_mL (1600).
Use only the supplied fictional numbers. This worksheet neither selects nor validates a clinical dose.
=IF(OR(COUNT(D2:F2)<>3,D2<0,E2<=0,F2<=0),"Invalid inputs",ROUND((D2 * E2 * 60) / F2, 1))Try the example
Use the original values or change them to test your understanding.