Oklahoma Income Tax Calculator 2026

How Oklahoma income tax works in 2026

Oklahoma starts with federal AGI, applies Oklahoma additions and subtractions, then subtracts the Oklahoma standard deduction ($6,350 single, $12,700 joint, $9,350 head of household) and $1,000 for each exemption. The 2026 rate schedule has a 0% band followed by rates of 2.5%, 3.5%, 4.5%.

Worked example: $55,000 single filer

A single filer with $55,000 of wages subtracts the $6,350 standard deduction and one $1,000 exemption, for Oklahoma taxable income of $47,650:

• Oklahoma tax: $1,930, or 3.51% of wages — almost all of the taxable income falls in the top band.

Retirement income in Oklahoma

Oklahoma has several retirement exclusions, claimed on Schedule 511-A:

• Social Security benefits included in federal AGI are subtracted in full.
• Military retirement: each individual may exclude 100% of retirement benefits from any component of the U.S. Armed Forces.
• Federal Civil Service Retirement System (CSRS) benefits paid in lieu of Social Security are 100% excludable; most FERS benefits are not.
• Other retirement benefits — Oklahoma government plans, private pensions, IRAs and 401(k) plans — can be excluded up to $10,000 per person, limited to the amount in federal AGI.

Oklahoma credits and deductions

Oklahoma’s credits are modest percentages of federal credits, so they mainly help families who already qualify federally:

• Child care / child tax credit: if federal AGI is $100,000 or less, the greater of 20% of the federal child care credit or 5% of the federal child tax credit.
• Earned income credit: 5% of the federal earned income credit.
• Oklahoma 529 college savings contributions: deductible up to $10,000 a year ($20,000 joint), with a five-year carryforward.
• Sales tax relief credit for lower-income households, claimed on Form 538-S.

Filing your Oklahoma return

Residents file Form 511, due April 15 — or April 20 if you file electronically. Part-year residents and nonresidents file Form 511-NR; a nonresident must file if they have $1,000 or more of gross income from Oklahoma sources. A valid federal extension also extends the Oklahoma filing date, but at least 90% of the tax must be paid by the original due date to avoid a late-payment penalty.