Monitor Unit (MU) Calculator

Calculation Parameters

Beam Energy

Prescribed Dose (cGy)

Depth (cm)

Field Size

×

SSD (cm)

Dose Calculation Method

Calculation Results

MU Calculation Formula

MU = Prescribed Dose / (OF × PDD/TMR × CF)

Where:

OF = Output Factor
PDD = Percent Depth Dose / 100
TMR = Tissue Maximum Ratio
CF = Calibration Factor (1.0 cGy/MU)

Reference: Output Factors

Field Size (cm²)	6 MV	10 MV	15 MV	18 MV
5×5	0.968	0.971	0.973	0.974
10×10	1.000	1.000	1.000	1.000
15×15	1.021	1.018	1.016	1.015
20×20	1.035	1.030	1.027	1.025
25×25	1.046	1.040	1.036	1.034
30×30	1.055	1.048	1.043	1.041
40×40	1.069	1.060	1.054	1.051