Paycheck Calculator

Paycheck is evaluated from Gross Pay per Paycheck, Pay Frequency and Filing Status. The calculation reports Federal Income Tax Withheld, Social Security Tax and Medicare Tax.

Results

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About the Paycheck Calculator

Paycheck is treated here as a quantitative relation between Gross Pay per Paycheck, Pay Frequency, Filing Status and Pre-Tax 401 Contribution and Federal Income Tax Withheld, Social Security Tax, Medicare Tax and Net Take-Home Pay.

The calculator uses a custom php logic configuration. Each reported value is read as a direct evaluation of the stored rules with the declared field formats and units.

Formula basis:
Pre-Tax Gross = Gross Pay - 401(k) Deduction - Health Insurance
FICA Base = Gross Pay (FICA is on full wages)
Social Security = min(Gross Pay, remaining SS wage base) x 6.2%
Medicare = Gross Pay x 1.45% (+0.9% if above thresholds)
Federal Tax = Annualized withholding based on W-4 and 2024 tax tables / pay periods
Net Pay = Gross Pay - Federal Tax - Social Security - Medicare - Pre-Tax Deductions

Interpret the outputs in the order shown by the result fields. Optional inputs affect only the outputs that depend on those variables.

Formula & How It Works

The calculation applies the following relations exactly as recorded in the metadata:

Pre-Tax Gross = Gross Pay - 401(k) Deduction - Health Insurance
FICA Base = Gross Pay (FICA is on full wages)
Social Security = min(Gross Pay, remaining SS wage base) x 6.2%
Medicare = Gross Pay x 1.45% (+0.9% if above thresholds)
Federal Tax = Annualized withholding based on W-4 and 2024 tax tables / pay periods
Net Pay = Gross Pay - Federal Tax - Social Security - Medicare - Pre-Tax Deductions

Each output field is produced by substituting the supplied inputs into the relevant relation and then applying the declared rounding or text format.

Worked Examples

Example 1: Bi-Weekly Paycheck — Single

Inputs

gross_pay: 3000 pay_frequency: 26 filing_status: single pretax_401k: 10 pretax_health: 200
Federal Income Tax Withheld: $331.12. Social Security Tax: $186. Medicare Tax: $43.5. Net Take-Home Pay: $2,439.38. Effective Tax Rate: 18.69%

With Gross Pay per Paycheck = 3,000, Pay Frequency = 26, Filing Status = single and Pre-Tax 401 Contribution = 10 as the stated inputs, the result is Federal Income Tax Withheld = $331.12, Social Security Tax = $186 and Medicare Tax = $43.5. Each value corresponds to the declared output fields.

Example 2: Married Filing Jointly — Semi-Monthly

Inputs

gross_pay: 4500 pay_frequency: 24 filing_status: mfj pretax_401k: 8 pretax_health: 350
Federal Income Tax Withheld: $376.27. Social Security Tax: $279. Medicare Tax: $65.25. Net Take-Home Pay: $3,779.48. Effective Tax Rate: 16.01%

With Gross Pay per Paycheck = 4,500, Pay Frequency = 24, Filing Status = mfj and Pre-Tax 401 Contribution = 8 as the stated inputs, the result is Federal Income Tax Withheld = $376.27, Social Security Tax = $279 and Medicare Tax = $65.25. Each value corresponds to the declared output fields.

Example 3: High Earner — Monthly Paycheck

Inputs

gross_pay: 15000 pay_frequency: 12 filing_status: single pretax_401k: 13 pretax_health: 400
Federal Income Tax Withheld: $3,866.72. Social Security Tax: $419.93. Medicare Tax: $217.5. Net Take-Home Pay: $10,495.85. Effective Tax Rate: 30.03%

With Gross Pay per Paycheck = 15,000, Pay Frequency = 12, Filing Status = single and Pre-Tax 401 Contribution = 13 as the stated inputs, the result is Federal Income Tax Withheld = $3,866.72, Social Security Tax = $419.93 and Medicare Tax = $217.5. Each value corresponds to the declared output fields.

Example 4: Low Income — Head of Household

Inputs

gross_pay: 1800 pay_frequency: 26 filing_status: hoh pretax_401k: 3 pretax_health: 120
Federal Income Tax Withheld: $134.13. Social Security Tax: $111.6. Medicare Tax: $26.1. Net Take-Home Pay: $1,528.17. Effective Tax Rate: 15.1%

With Gross Pay per Paycheck = 1,800, Pay Frequency = 26, Filing Status = hoh and Pre-Tax 401 Contribution = 3 as the stated inputs, the result is Federal Income Tax Withheld = $134.13, Social Security Tax = $111.6 and Medicare Tax = $26.1. Each value corresponds to the declared output fields.

Common Use Cases

  • Calculate your exact take-home pay after taxes and deductions
  • Compare net pay impact of changing 401(k) contribution
  • Estimate paycheck after a raise or new job offer