Salary
Total tax
Add the rates first, then apply once. Multiplying separately and adding gives the same answer.
The Formula
tax = gross x (federal + state + payroll)
Add the rates first, then apply once. Multiplying separately and adding gives the same answer.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| T | Total tax | currency | Combined tax withheld. |
| G | Gross pay | currency | Total pay before deductions. |
| f | Federal rate | ratio | Federal income tax rate. |
| s | State rate | ratio | State income tax rate. |
| p | Payroll rate | ratio | Social Security and Medicare rate. |
What Each Symbol Means
Tcurrency
Total tax
Combined tax withheld.
Gcurrency
Gross pay
Total pay before deductions.
fratio
Federal rate
Federal income tax rate.
sratio
State rate
State income tax rate.
pratio
Payroll rate
Social Security and Medicare rate.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate take home pay page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Take Home Pay, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.