How the Turkey net maaş calculator is verified

Inputs

InputFieldType
Yıllık brüt (TRY)grossAnnualnumber

The formula

Each derived value below is computed by the Valem engine from the expression shown, in this order. Nothing else runs — there is no hidden code path.

Derived valueFieldFormula (JSONata)
SGK + işsizliksgk$round(grossAnnual * $const.sgkRate, 2)
Taxabletaxable$round(grossAnnual - sgk, 2)
Gelir vergisiincomeTax($t := taxable; $round((($t < $const.b1 ? $t : $const.b1) * 0.15) + (($t > $const.b1 ? (($t < $const.b2 ? $t : $const.b2) - $const.b1) : 0) * 0.20) + (($t > $const.b2 ? (($t < $const.b3 ? $t : $const.b3) - $const.b2) : 0) * 0.27) + (($t > $const.b3 ? (($t < $const.b4 ? $t : $const.b4) - $const.b3) : 0) * 0.35) + (($t > $const.b4 ? ($t - $const.b4) : 0) * 0.40), 2))
Damga vergisistampDuty$round(grossAnnual * $const.stampRate, 2)
Net / yılnetAnnual$round(grossAnnual - sgk - incomeTax - stampDuty, 2)
Net / aynetMonthly$round(netAnnual / 12, 2)

Rates and thresholds

The expressions above read these as $const. They are the figures the annual refresh replaces, so they live as data rather than being written into the formulas — which is what makes a year-on-year change a one-line diff instead of an edit to arithmetic.

ConstantValue
sgkRate0.15
stampRate0.00759
b1158000
b2330000
b31200000
b44300000

Test vectors (2)

Every case is executed against this model on each build, by the Java engine and independently by a JavaScript one. A mismatch of a single cent fails the build, so the page cannot ship advertising a figure the model no longer produces.

Case 1 — S1 720,000 TRY/yr (60k/mo)

given grossAnnual720000
expect sgk108000
expect incomeTax134240
expect stampDuty5464.8
expect netAnnual472295.2

Case 2 — S2 1,500,000 TRY/yr

given grossAnnual1500000
expect sgk225000
expect incomeTax319250

Sources

Check it yourself — and reuse it

The whole model as JSON — inputs, outputs, formulas, vectors and sources in one re-runnable document.

This model is published under CC BY 4.0: use it, adapt it, build on it, with attribution. The licence covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds are law, and nobody licenses those; the sources above are where they come from.

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