Utah State Income Tax Calculator

We apply Utah’s flat rate for the selected year to the annualized taxable base, then subtract nonrefundable credits (capped at the pre-credit tax).

Given pay frequency factor f, gross per period G, pre-tax per period P, annual additions A, annual subtractions S, annual credits C, and rate r:

$$ \begin{aligned} \text{Annual Gross} \; AG &= G \times f \\ \text{Annual Pre-tax} \; AP &= P \times f \\ \text{Taxable Base} \; T &= \max\big(0,\; AG - AP + A - S\big) \\ \text{Pre-credit Tax} \; PC &= r \times T \\ \text{Credits Applied} \; C_a &= \min(C,\; PC) \\ \text{Tax After Credits} \; TAC &= PC - C_a \\ \text{Effective Rate} \; e &= \begin{cases} \dfrac{TAC}{AG} & AG > 0 \\ 0 & AG = 0 \end{cases} \\ \text{Per-Period Tax} \; t_p &= \dfrac{TAC}{f} \end{aligned} $$

Annualize gross and pre-tax:

$$ AG = 6000 \times 12 = 72{,}000 \qquad AP = 400 \times 12 = 4{,}800 $$

Taxable base:

$$ T = \max\big(0, 72{,}000 - 4{,}800 + 0 - 0\big) = 67{,}200 $$

Pre-credit tax:

$$ PC = 0.0455 \times 67{,}200 = 3{,}057.60 $$

Credits applied (capped to PC):

$$ C_a = \min(300,\; 3{,}057.60) = 300 $$

Tax after credits:

$$ TAC = 3{,}057.60 - 300 = 2{,}757.60 $$

Effective rate and per-period tax:

$$ e = \frac{2{,}757.60}{72{,}000} \approx 3.83\% \qquad t_p = \frac{2{,}757.60}{12} = 229.80 $$