CBCT Radiation Dose Calculator

Effective dose from CBCT FOV and protocol.

Medical Disclaimer

This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.

Inputs

Field of view

Tube voltage (kVp)

Tube current (mA)

Exposure time (sec)

Voxel size (um)

Rotation arc (deg)

Scans per year (facility)

Patient age (years)

Tab to move between fields

Results

Effective dose (uSv)

Age-adjusted dose (uSv)

Equivalent panoramics5

Background equivalent (days)9.4

% of medical CT head5

Operator annual dose (mSv)0.02

% of occupational limit0.08

Fov NameMedium (8x8 cm)

How to Use This Calculator

Select the Field of View size appropriate for the clinical task.
Enter Tube Voltage (kVp), Tube Current (mA), and Exposure Time (sec).
Set the Voxel Size and Rotation Arc for your scan protocol.
Enter Patient Age to calculate the age-adjusted effective dose.
Review Effective Dose (uSv) and compare to daily background dose to justify CBCT use.

How the result changes with Tube voltage (kVp)

Tube voltage (kVp)	Effective dose (uSv)	Age-adjusted dose (uSv)
66	34.5	34.5
81	57.6	57.6
99	95.2	95.2
114	135.4	135.4

What each input means

Field of view: Select CBCT field of view size.
Tube voltage (kVp): Kilovoltage peak — typically 60-120 kVp for dental CBCT.
Tube current (mA): Milliamperage — typically 2-15 mA for dental CBCT.
Exposure time (sec): Total scan time in seconds (typically 5-20s).
Voxel size (um): Voxel resolution in micrometers (75-600 um). Smaller = higher resolution but more dose.
Rotation arc (deg): Gantry rotation in degrees (180 or 360).
Scans per year (facility): Total CBCT scans performed annually at your practice.
Patient age (years): Patient age — children receive higher biological dose due to radiosensitivity.

What each result means

Effective dose (uSv): Estimated effective dose in microsieverts.
Age-adjusted dose (uSv): Dose adjusted for age-based radiosensitivity.
Equivalent panoramics: Number of panoramic radiographs that deliver the same dose.
Background equivalent (days): Days of natural background radiation delivering the same dose.
% of medical CT head: This dose as a percentage of a typical medical CT of the head (~1500 uSv).
Operator annual dose (mSv): Estimated annual dose to shielded operator at 2m.
% of occupational limit: Operator dose as percentage of the 20 mSv/year ICRP occupational limit.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Field of view = 1, Tube voltage (kVp) = 90, Tube current (mA) = 8, Exposure time (sec) = 8 = 8 input(s) provided
Calculate Effective dose
Effective dose = baseDose * kvpFactor * mAFactor * timeFactor * rotationFactor * voxelFactor
75 = 75
Calculate Age-adjusted dose
Age-adjusted dose = effectiveDoseUSv * ageFactor
75 = 75
Calculate Equivalent panoramics
Equivalent panoramics = effectiveDoseUSv / 15
5 = 5
Calculate Background equivalent
Background equivalent = effectiveDoseUSv / 8
9.4 = 9.4