Three worked examples, line by line
Each example is one pay period. The two year-to-date figures decide where that period sits against the two federal caps, and every dollar below is computed from those three inputs rather than copied from another printed figure.
Example A — a period early in the year, with both caps still far away
Gross $3,000.00; Social Security wages before this period $0.00; Medicare wages before this period $0.00
Social Security — the whole $3,000.00 is under the $184,500.00 base: $3,000.00 × 6.2% = $186.00
Medicare — $3,000.00 × 1.45% = $43.50; Additional Medicare — no wages above $200,000.00, so $0.00
Total FICA = $186.00 + $43.50 + $0.00 = $229.50
Example B — the period that crosses the Social Security wage base
Gross $5,000.00; Social Security wages before this period $182,000.00; Medicare wages before this period $182,000.00
Social Security — only $184,500.00 − $182,000.00 = $2,500.00 of this check is still taxable: $2,500.00 × 6.2% = $155.00
Medicare — $5,000.00 × 1.45% = $72.50; Additional Medicare — $187,000.00 is still under $200,000.00, so $0.00
Total FICA = $155.00 + $72.50 + $0.00 = $227.50
Example C — the period that crosses $200,000 and starts the Additional Medicare line
Gross $12,000.00; Social Security wages before this period $196,000.00; Medicare wages before this period $196,000.00
Social Security — the $184,500.00 base was passed before this period, so $0.00 of this check is taxable
Medicare — $12,000.00 × 1.45% = $174.00; Additional Medicare — $196,000.00 + $12,000.00 − $200,000.00 = $8,000.00 × 0.9% = $72.00
Total FICA = $0.00 + $174.00 + $72.00 = $246.00
The same three examples, side by side
| Example | Gross this period | Social Security | Medicare | Additional Medicare | Total FICA |
| A | $3,000.00 | $186.00 | $43.50 | $0.00 | $229.50 |
| B | $5,000.00 | $155.00 | $72.50 | $0.00 | $227.50 |
| C | $12,000.00 | $0.00 | $174.00 | $72.00 | $246.00 |
Why one paycheck can have three different taxable amounts
The three lines above do not share a base. Social Security has a ceiling that runs out part-way through a year; Medicare has no ceiling at all; the Additional Medicare line begins only at a threshold. That is why a single gross figure produces three different taxable amounts, and why a calculator that multiplies one rate by gross three times will be wrong on at least one of them.
Example B is the clearest case. The check is $5,000.00, and exactly half of it — $2,500.00 — still sits under the Social Security base. Medicare nevertheless sees the full $5,000.00. If both lines had used the same $2,500.00, the Medicare figure would have come out $36.25 instead of $72.50, and the check would be understated by that same amount. The wage base limits one line; it does not shorten the period.
Example C runs the other way. Social Security contributes nothing because the base was passed in an earlier period, while the Additional Medicare line appears for the first time in this one. The $8,000.00 that triggers it is the tail of this check, not the whole check: $196,000.00 of earlier wages plus $12,000.00 now puts $8,000.00 above $200,000.00. Entering a gross figure without the year-to-date figures cannot produce that split, because the threshold is measured across the calendar year rather than across one pay period.
None of this needs a state rule. The two year-to-date boxes are inputs you bring from a pay stub; the calculator only subtracts, multiplies and adds them. If your payroll also withholds something this page does not cover, the other-withholding box takes a dollar amount you type yourself, and the figure below the results shows it separately.
What the pages at the top of the results did not show
We read the natural results for this phrase once, on 10 November 2026, in the browser we use for research. Nine results came back. Four answered with an access-denied response and are recorded as unreadable, not as zero. The following counts come from the five pages we could read.
| What we looked for | Result across the five readable pages |
| A line splitting one paycheck at the wage base | Zero matches on all five |
| A labelled worked example | Zero matches on all five |
| Any mention of the Social Security wage base | Three of five had none |
| Any year-to-date reference | Three of five had none |
| A date attached to sources | One of five had one |
These are counts of the phrases we looked for in those pages that day, written from our own notes; they are not a claim about what those sites do elsewhere, and we have not copied a sentence from any of them. What this page adds is narrow and specific: the split itself, printed line by line for three periods, with the two caps and the year-to-date figures visible as inputs rather than described in prose.
Texas state rules and the sources behind this page
This page quotes no Texas statute, no state tax rate, no pay frequency, no deadline and no penalty. Where we could not reach a primary Texas source today, the table below says “Source not found” rather than carrying a plausible-sounding number.
On 10 November 2026 we tried four official Texas addresses in the browser used for this research. Each navigation ended at a name-resolution error, and a direct fetch returned no response. We therefore did not quote a state income tax rule, a local tax rule or a payday rule. A row we cannot source stays as a gap; a number that cannot be traced is worse than a blank.
The only rates on this page are federal, and they come from IRS Publication 15, read on 10 November 2026: Social Security at 6.2% of wages up to a $184,500.00 wage base, Medicare at 1.45% of all wages with no wage base limit, and 0.9% Additional Medicare Tax on wages above $200,000.00 in a calendar year. Those are the only constants in the calculator, and each one appears in the working printed above.
Source check, 10 November 2026
| Item | Source |
| Texas state income tax rule | Source not found |
| Texas local income tax rule | Source not found |
| Texas payday or pay frequency rule | Source not found |
| Federal FICA rates and wage base | IRS Publication 15, read 10 November 2026 |
| Additional Medicare threshold | IRS Publication 15, read 10 November 2026 |
| Calculator arithmetic | Printed line by line above |
| Published | 10 November 2026 |