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mL/hr to mg/kg/hr Calculator

Convert an infusion pump rate (mL/hr) into a weight-based dose (mg/kg/hr) using concentration (mg/mL) and patient weight (kg).

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Pump rate in mL per hour (commas accepted).

How many mg are in each 1 mL.

Use actual body weight unless protocol says otherwise.

How mL/hr to mg/kg/hr Conversion Works

Infusion pumps are often programmed in mL per hour (mL/hr), while medication strength is expressed as mg per mL (mg/mL). That gets you a dose rate in mg/hr.

If a protocol requires a weight-based dose, you then divide the mg/hr by the patient’s weight (kg) to obtain mg/kg/hr. This is common in paediatrics and some adult critical-care protocols where dose targets scale by size.

Formula

mg/hr = (mL/hr) × (mg/mL)
mg/kg/hr = (mg/hr) ÷ (kg)
Optional: mg/kg/min = (mg/kg/hr) ÷ 60

Worked Examples

Example 1: Rate 10 mL/hr, concentration 2 mg/mL, weight 80 kg. What is mg/kg/hr?

mg/hr = 10 × 2 = 20 mg/hr
mg/kg/hr = 20 ÷ 80 = 0.25 mg/kg/hr
Answer: 0.25 mg/kg/hr

Example 2: Rate 12 mL/hr, concentration 1.5 mg/mL, weight 60 kg. What is mg/kg/hr?

mg/hr = 12 × 1.5 = 18 mg/hr
mg/kg/hr = 18 ÷ 60 = 0.30 mg/kg/hr
Answer: 0.30 mg/kg/hr

Example 3: Rate 2.5 mL/hr, concentration 4 mg/mL, weight 25 kg. What is mg/kg/hr?

mg/hr = 2.5 × 4 = 10 mg/hr
mg/kg/hr = 10 ÷ 25 = 0.40 mg/kg/hr
Answer: 0.40 mg/kg/hr

Clinical safety note: Confirm the concentration source (mg/mL), pump units (mL/hr), and weight units (kg). High-risk infusions may require an independent double-check and protocol-based rounding. This tool supports checking only.

Related Calculators

mL/hr to mg/hr

Rate × concentration

mL/hr to mg/min

Per-minute dosing

mL/hr to mg/kg/min

Weight-based per minute

mL/hr to mcg/kg/hr

Microgram weight-based

Frequently Asked Questions

Clinical reminder: Always follow local protocols and consult medication information sheets. These examples are for calculation practice only.

References & Sources

References focus on medication calculation concepts and medication safety principles.

NSQHS Medication Safety Standard Web

ACSQHC (Australia)

Medication safety principles relevant to preparation, checking, and administration.

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Institute for Safe Medication Practices (ISMP) Web

Medication safety resources

Safety concepts commonly applied to high-risk infusions and calculation checking.

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Pharmacy Calculations (concentration concepts) Web

NCBI Bookshelf (StatPearls)

General concentration and solution calculation structure used in infusion math.

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Clinical disclaimer: Educational checking tool only — always follow local policy and product guidance.

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