How the Türkiye serbest meslek calculator is verified

Inputs

Input	Field	Type
Annual income after expenses (TRY)	`annualIncome`	number

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 value	Field	Formula (JSONata)
Bagkur Base	`bagkurBase`	`$round($min([$max([annualIncome, $const.bagkurMinBase]), $const.bagkurMaxBase]), 2)`
Bağ-Kur premiums	`bagkurPremiums`	`$round(bagkurBase * $const.bagkurRate, 2)`
Taxable Income	`taxableIncome`	`$round($max([0, annualIncome - bagkurPremiums]), 2)`
Income tax	`incomeTax`	`($t := taxableIncome; $round($const.r1 * $min([$t, $const.b1]) + $const.r2 * $max([0, $min([$t, $const.b2]) - $const.b1]) + $const.r3 * $max([0, $min([$t, $const.b3]) - $const.b2]) + $const.r4 * $max([0, $min([$t, $const.b4]) - $const.b3]) + $const.r5 * $max([0, $t - $const.b4]), 2))`
Net income / year	`netIncome`	`$round($max([0, annualIncome - bagkurPremiums - incomeTax]), 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.

Constant	Value
`bagkurRate`	0.3575
`bagkurMinBase`	396360
`bagkurMaxBase`	3567240
`b1`	190000
`b2`	400000
`b3`	1000000
`b4`	5300000
`r1`	0.15
`r2`	0.2
`r3`	0.27
`r4`	0.35
`r5`	0.4

Test vectors (3)

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 — 1,200,000 TRY income — a typical full-time professional

given `annualIncome`	1200000
expect `bagkurBase`	1200000
expect `bagkurPremiums`	429000
expect `taxableIncome`	771000
expect `incomeTax`	170670
expect `netIncome`	600330

Case 2 — 300,000 TRY — below the Bağ-Kur minimum base

given `annualIncome`	300000
expect `bagkurBase`	396360
expect `bagkurPremiums`	141698.7
expect `taxableIncome`	158301.3
expect `incomeTax`	23745.19
expect `netIncome`	134556.11

Case 3 — 6,000,000 TRY — into the top bracket

given `annualIncome`	6000000
expect `bagkurBase`	3567240
expect `bagkurPremiums`	1275288.3
expect `taxableIncome`	4724711.7
expect `incomeTax`	1536149.1
expect `netIncome`	3188562.6

Sources

Gelir İdaresi Başkanlığı — Serbest meslek kazancının vergilendirilmesi · checked 2026-08-22
2026 gelir vergisi dilimleri (ücret dışı gelirler) ve Bağ-Kur prim oranı · checked 2026-08-22

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.

← Back to the Türkiye serbest meslek calculator

Built with Valem — a live, verifiable calculator you can fork and embed.