ADHD Dose Calculator

The ADHD Dose Calculator estimates appropriate medication dosages in milligrams based on patient weight, age, and specific drug selection. This tool helps healthcare providers quickly determine starting doses and titration schedules to optimize therapeutic levels. Whether you are initiating a new prescription, adjusting current treatment, or managing side effects, this calculator supports safe clinical decision-making.

How This Calculator Works

  1. Patient Summary: Enter the weight and age to establish the physiological baseline.
  2. Select Drug: Choose the medication type and specific drug name.
  3. Fine-Tuning: Set the formulation (IR/ER) and symptom severity.
  4. Dose Progression: The tool generates a starting dose, target dose, and a week-by-week titration plan.
Enter patient's weight in kilograms
Enter patient's age in years
Leave blank if this is a new prescription

Important: This tool is for informational purposes only and is not a substitute for professional medical advice, screening assessment, or treatment. Always consult with a qualified healthcare provider before prescribing or changing ADHD medications.

How Medication Dosage Is Calculated

Medication dosage represents the calculated amount of a drug required to manage ADHD symptoms effectively while minimizing risks. The calculation relies on a standard weight-based formula to determine the initial therapeutic amount.

Starting Dose = Weight (kg) × Dose Factor (mg/kg/day)

Where:

  • Weight = Patient's body weight in kilograms
  • Dose Factor = Medication-specific constant varying by drug type and age
  • Adjustments = Multipliers for formulation and symptom severity

First, the tool calculates a base dose using the patient's weight to ensure the amount is proportional to body size. Next, it refines this number by applying specific factors for the chosen medication and its formulation, such as extended release. Finally, adjustments are made for symptom severity and age-specific maximum limits to support informed decision-making and efficacy.

Medication FDA Approved Age Typical Starting Range
Methylphenidate (IR) 6+ years 5 mg once or twice daily
Amphetamine (ER) 6+ years 5 - 10 mg once daily
Atomoxetine 6+ years 0.5 mg/kg/day
Guanfacine (ER) 6 - 17 years 1 mg once daily

Standard FDA-approved age ranges and common starting dosages for ADHD pharmacotherapy.

What Your Medication Dosage Means

This result indicates the recommended daily amount of medication needed to effectively control symptoms based on current clinical guidelines. It serves as a foundational starting point that should be tailored to individual responses over time.

New Patient Initiation
For new prescriptions, start with the calculated low dose to assess tolerance. For example, a child might begin at 5-10 mg of a stimulant, increasing gradually to minimize side effects.

Titration for Optimization
If symptoms persist but the dose is well-tolerated, increase the dosage by the suggested titration step every week. Adults often require higher total daily doses than children to reach the optimal therapeutic window.

Managing Side Effects
If adverse effects occur, the calculated target dose may need to be lowered rather than increased. Always prioritize tolerability to ensure long-term adherence to the treatment plan.

Monitor the patient closely during the first few weeks of treatment and adjust the plan based on their specific response and feedback.

References

  • American Academy of Pediatrics (AAP) - Clinical Practice Guideline for ADHD
  • American Academy of Child and Adolescent Psychiatry (AACAP) - ADHD Practice Parameters
  • U.S. Food and Drug Administration (FDA) - Approved ADHD Medications

Frequently Asked Questions

Immediate Release (IR) medications release the drug into the system quickly and usually last 3-5 hours, requiring multiple doses per day. Extended Release (ER/XR) medications are designed to release the drug slowly over 8-12 hours, typically requiring only one dose in the morning.

Titration is the process of gradually increasing the dose of a medication to find the "therapeutic window"—the point where management of symptoms is optimized with the fewest possible side effects.

While weight-based dosing is a standard starting point for children, adult dosing for stimulants is often less dependent on weight and more dependent on individual metabolism and sensitivity. Adults usually start at a low standard dose regardless of weight.

Calculation logic verified using publicly available standards.

View our Accuracy & Reliability Framework →