Per Capita

Hi _Junayetrahman ,

First allow me to correct an error in your calculations:

78531/(2/12)=471186

The Total Per Capita Amount at the end is the same reason why my calculations are off from what you want them to be.
I create a slicer to select 2021, 2022 or 2023.
Please Please refer to the following DAXs:

per capita amount for A = 
VAR Total_amount = 
CALCULATE(
    SUM('Table'[Amount]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "A" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
VAR Total_month = 
CALCULATE(
    DISTINCTCOUNT('Table'[Month]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "A" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
RETURN
Total_amount / (Total_month / MAX('Table'[Month])

per capita amount for B = 
VAR Total_amount = 
CALCULATE(
    SUM('Table'[Amount]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "B" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
VAR Total_month = 
CALCULATE(
    DISTINCTCOUNT('Table'[Month]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "B" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
RETURN
Total_amount / (Total_month / MAX('Table'[Month])

per capita amount for C = 
VAR Total_amount = 
CALCULATE(
    SUM('Table'[Amount]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "C" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
VAR Total_month = 
CALCULATE(
    DISTINCTCOUNT('Table'[Month]),
    FILTER(
        ALL('Table'),
        'Table'[Employee name] = "C" && 'Table'[Year] = SELECTEDVALUE('Table'[Year])
    )
)
RETURN
Total_amount / (Total_month / MAX('Table'[Month]))

Total Per Capita Amount = 
VAR Total_Amount = SUM('Table'[Amount])
VAR Month_A_2021 = CALCULATE(DISTINCTCOUNT('Table'[Month]), FILTER(ALL('Table'), 'Table'[Employee name] = "A" && 'Table'[Year] = 2021))
VAR Month_B_2022 = CALCULATE(DISTINCTCOUNT('Table'[Month]), FILTER(ALL('Table'), 'Table'[Employee name] = "B" && 'Table'[Year] = 2022))
VAR Month_C_2022 = CALCULATE(DISTINCTCOUNT('Table'[Month]), FILTER(ALL('Table'), 'Table'[Employee name] = "C" && 'Table'[Year] = 2022))
VAR Month_C_2023 = CALCULATE(DISTINCTCOUNT('Table'[Month]), FILTER(ALL('Table'), 'Table'[Employee name] = "C" && 'Table'[Year] = 2023))
VAR Month_2021 = CALCULATE(MAX('Table'[Month]), FILTER(ALL('Table'), 'Table'[Year] = 2021))
VAR Month_2022 = CALCULATE(MAX('Table'[Month]), FILTER(ALL('Table'), 'Table'[Year] = 2022))
VAR Month_2023 = CALCULATE(MAX('Table'[Month]), FILTER(ALL('Table'), 'Table'[Year] = 2023))
RETURN
Total_Amount / ((Month_A_2021 / Month_2021) + (Month_B_2022 / Month_2022) + (Month_C_2022 / Month_2022) + (Month_C_2023 / Month_2023))

The results are shown below:

Best Regards,
Dino Tao
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