D = E / m | Absorbed Dose, Energy, Mass | Health Physics & Radiology Tool
Result
--
📝 Step-by-step solution
Select what to calculate and enter values
💡 Absorbed dose D in Gray (Gy) = J/kg | Energy E in Joules | Mass m in kg | 1 Gy = 1 J/kg
📖 How to Use This Radiation Dose Calculator
1
Select what to calculate - Choose Absorbed Dose (D), Energy (E), or Mass (m).
2
Enter known values - Input the two known quantities based on the formula D = E/m.
3
Click "Calculate" - Get the result with step-by-step solution.
☢️ Understanding Absorbed Radiation Dose
Absorbed dose is the amount of energy deposited by ionizing radiation per unit mass of material. The fundamental formula is D = E/m, where D is absorbed dose in Gray (Gy), E is energy in Joules, and m is mass in kilograms.
One Gray (Gy) equals one Joule of energy absorbed per kilogram of matter (1 Gy = 1 J/kg). This measurement is crucial in radiology, radiation therapy, nuclear medicine, and radiation protection.
📊 Key Radiation Dose Formulas
Absorbed Dose: D = E / m Energy: E = D × m Mass: m = E / D
💡 Important Radiation Units
Gray (Gy): Absorbed dose - 1 Gy = 1 J/kg
Sievert (Sv): Equivalent dose (biological effect)
Rad: 1 Gy = 100 rad (older unit)
Rem: 1 Sv = 100 rem
📊 Typical Radiation Doses
Chest X-ray: 0.02-0.1 mSv
CT Scan (head): 1-2 mSv
Annual background: 2-3 mSv/year
Radiation therapy: 2 Gy per session
Acute radiation sickness: 0.5-1 Gy
LD50/60: 3-5 Gy whole body
❓ Frequently Asked Questions
What is the difference between Gray (Gy) and Sievert (Sv)?
Gray measures absorbed dose (energy deposited per mass). Sievert measures equivalent dose (biological effect). For X-rays and gamma rays, 1 Gy ≈ 1 Sv.
What is a safe radiation dose?
Average annual background: 2-3 mSv. Occupational limit: 50 mSv/year. Public limit: 1 mSv/year above background.
How does mass affect absorbed dose?
For the same energy, larger mass means lower absorbed dose. This is why radiation protection uses shielding.
What is the ALARA principle?
ALARA stands for "As Low As Reasonably Achievable" - the guiding principle of radiation protection.