## Clarks Rule, Body Weight Base Child Drug Dose Calculator

Quickly calculate pediatric drug dose based on Body Weight, Clarks Rule (formula). Weight based pediatric drug dose calculator.

**Clarks Rule**

**Clarks rule** is an equation used to calculate pediatric drug dose dosage based on the known weight of a patient and a known adult dose of medication to be used.

It is used to calculate child drug dose based on body weight.

## Clarks Formula

Clark’s rule Formula can be characterized as the weight of the patients in pounds divided by the average standard weight of 150 pounds (68kg) multiplied by the adult dose of a drug equals the pediatric medication dose. Its formula as expressed beneath:

or Childs dose = Weight (kg)/ 68 × adult dose

### Calculation Examples 1

Calculate childs drug dose when weight is in pounds (lbs)

Using Clark’s rule, if an adult dose of medications calls for 30mg and the child weighs 30 lbs, what is the child dose?

**Answer:**

Child dose= 30Ibs/150Ibs*30mg =6mg of medicine

### Calculation Examples 2

Calculate childs drug dose when weight is in kilogram (kg)

Using Clark’s rule, what is the dose for a twelve yr old male who weighs 35kg, if the average adult dose is 500mg?

**Answer:**

Child dose= 35kg/68kgs*500mg =257mg of medicine

### General Tips

- Check that your answer makes sense clinically.
- Triple check your work.
- Have a colleague or pharmacist check your work.
- Know general therapeutic drug doses for commonly administered medications.

### Clarks Rule Limitations

Clark’s Rule assumes that children have similar pharmacokinetic and pharmacodynamic properties as adults. However, younger children or infants may not always fit this assumption. Always consult with a healthcare professional to ensure accurate dosing and maximize safety.

## How to Use Body Weight Base Medication Dosing Calculator?

- Select weight unit (kg or lbs)
- Enter Childs Weight
- Plugging in adult drug dose.
- Click on “Calculate” button and childs medication dose will appear below.

**Click here to calculate your Body Mass Index.**

If you are interested in different measurements related to Childs Drug Dose, **you should also check our:**

- BSA Based pediatric drug dose calculator
- Child Drug Dose Calculators based on age using:

## FAQs

##### What is Clarks Rule?

**Clarks rule** is an equation used to calculate pediatric drug dose dosage based on the known weight of a patient and a known adult dose of medication to be used.

##### What is Clarks Formula?

Clark’s rule Formula can be characterized as the weight of the patients in pounds divided by the average standard weight of 150 pounds (68kg) multiplied by the adult dose of a drug equals the pediatric medication dose.

##### How do I calculate pediatrics drug dose based on weight?

Use Clark’s formula to calculate the pediatric drug dose based on body weight.

##### How do I calculate child drug dose with weight in kilograms (kg)?

Simply apply Clark’s Rule (For kg) when you measure weight in kilograms (kg).

**Childs dose = Weight (kg)/ 68 × adult dose**

##### What are the other equations that utilize pediatric weight to calculate medication dosing?

Other equations that utilize pediatric weight to calculate medication dosing are Salisbury’s rule, Penna’s rule, and the Body Surface Area rule.

### Nursing, Allied Health, and Interprofessional Team Interventions

Nursing and pharmacy should be familiar with Clark’s rule since they will prepare, dispense, and administer medications to infants and children. This way, they can add another layer of safety when administering drugs to children and reach out to the prescribing or ordering clinician if they suspect an incorrect dose when using Clark’s rule. This interprofessional system of checks and balances can optimize patient outcomes.