## Fried’s Rule Calculator, Age-Based Drug Dose Calculator

Use this Fried’s Rule Formula to calculate pediatric drug doses for children under 1 year of age! (Fried’s Rule Calculator).

**Fried’s Rule**

**Frieds Rule** is another method used to calculate the correct dose of medication for the pediatric patient when given only the adult dose.

Use fried’s rule to calculate an infant dosage for patients under 24 months of age when a proper dosage has not already been determined.

## Fried’s Rule Formula

Express Fried’s Rule Formula as the child’s age in months divided by 150, multiplied by the adult drug dose, to equal the pediatric drug dose.

Fried’s (Solomon) rule =

[age(months)/150] × adult dose

### Calculation Examples

Learn how to use Fried’s rule formula to calculate pediatric drug doses.

If an adult dose of a particular medication is 50 mg, what is the dosage of a 10- month-old infant?

**Answer:**

Child dose= 10/150x 50 mg = **3.33mg** of medicine

### General Tips

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

## How to Use Fried’s Rule Calculator?

Age-Based Pediatric Drug Dose Calculator:

- Enter age in months.
- Enter adult drug dose
- Click on “Calculate” button.

- The calculator displays the child’s drug dose below.

**Click here to calculate your Body Mass Index (BMI).**

**To calculate your Body Surface Are (BSA) click here.**

Check our resources if you are interested in different measurements related to Child’s Drug Dose:

- Use the Clarks rule for the Weight-Based pediatric drug dose calculator.
- Utilize the Pediatric BSA Dose Calculator.
- Child Drug Dose Calculators based on age using:

## FAQs

**1. What is Fried’s Rule?**

Fried’s Rule is a method used in pediatric medicine to calculate the dosage of a drug for a child. It is based on the child’s age and is typically used for infants younger then 2 years of age.

**2. What is Fried’s Rule Formula?**

- The rule states that the child’s dose is equal to the child’s age in month divided by the 150, multiplied by the adult dose. This rule ensures that children receive a safe and effective dose of medication.

**Child Dosage = (Age in months / 150) × Adult Dosage**

**3. What age group is Fried’s Rule applicable to?**

- Fried’s Rule specifically applies to infants younger than 2 years of age.

**4. Can Fried’s Rule be used for older children?**

- No, healthcare providers should only use Fried’s Rule for infants under 2 years of age. For older children, healthcare providers should use other dosage calculation methods.

### More Calculation Examples:

**How to use Fried’s Rule to determine the adult dosage if a child 3 months old took a 50 mL dosage of medicine?**

Fried’s Rule states that the child’s dosage proportionally correlates with the adult dosage based on the child’s age in months divided by 150.

**Answer**:

Here is the formula based on Fried’s Rule:

*Child Dosage* = (Age in months / 150) × Adult Dosage

Now, let’s calculate:

- Age of the child: 3 months
- Known child dosage: 50 mL

Let’s rearrange the formula to solve for the Adult Dosage.

*Adult Dosage = (Child Dosage / (Age in months / 150))*

Thus,

- Adult Dosage = 50 mL / (3 months / 150)
- Adult Dosage = 50 mL / (0.02) = 2500 mL

Therefore, according to Fried’s Rule, the adult dosage would be 2500 mL if a 3-month-old child took a 50 mL dosage of the same medicine.

**A physician orders diphenhydramine 50mg oral administration every six hours PRN for pediatric patient who admitted to the hospital. Calculate the dose for a 22 month old child using Fried’s rule?**

**Answer**:

Let’s calculate:

- Age of the child: 22 months
- Known adult dosage: 50 mg

Here is the formula based on Fried’s Rule:

*Child Dosage = (Age in months / 150) × Adult Dosage*

Thus.

*Child Dosage *=(22months/150)*×*50mg = 0.15*×*50mg

*Child Dosage *= 7.5mg of diphenhydramine.