PBPowerballTax

Methodology

How the calculator is calculated

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Every result comes from three inputs and one formula. This page documents the formula, the data sources behind each rate, and the simplifications we deliberately make.

Federal tax

The IRS requires the lottery to withhold 24% of any prize over $5,000 at the source. Because lottery winnings are treated as ordinary income, large jackpots also cross into the 37% top marginal bracket. We model the gap as an additional 13% (=37% − 24%) applied only to payout above the 2026 single-filer top-bracket threshold of $640,600.

State tax

We use the headline state income-tax rate as of the 2026 tax year, sourced from state lottery disclosures and cross-checked against the Tax Foundation. The full table is published at /data/tax-rates.md.

Cash value

When a user picks the lump sum option, gross payout is estimated at 60% of the advertised annuity jackpot. The Multi-State Lottery Association publishes 60% as a long-run modelling approximation; actual cash-value ratios range from roughly 46% to 62% depending on Treasury rates at the time of the draw.

The formula

grossPayout = payoutMode == "cash"
  ? advertisedJackpot * 0.60
  : advertisedJackpot

federalWithholding   = grossPayout * 0.24
topBracketExposure   = max(grossPayout - 640_600, 0)
additionalFederalTax = topBracketExposure * 0.13
stateTax             = grossPayout * stateRate

totalTax    = federalWithholding + additionalFederalTax + stateTax
netPayout   = max(grossPayout - totalTax, 0)
effective   = totalTax / grossPayout

What the calculator intentionally does NOT model

  • City / county taxes (e.g. New York City 3.876%, Yonkers 1.477%).
  • Filing status other than single-filer (joint, head of household, dependents).
  • Itemised deductions, charitable offsets, or estate-planning strategies.
  • Investment return on the lump sum vs. the annuity — we display the pre-tax math only.
  • Time value of the 30-year annuity payments — future dollars are treated nominally.

Sources

  • Multi-State Lottery Association — cash-value ratio and payout rules. https://www.musl.com
  • Powerball.com — jackpot, cash value, next-draw dates. https://www.powerball.com
  • IRS Publication 17 — taxable income, lottery treatment. https://www.irs.gov
  • Tax Foundation — state individual income tax rates. https://taxfoundation.org
  • USAMega.com — independent lottery reference. https://www.usamega.com

Review cadence

State rates are reviewed quarterly against Tax Foundation releases and state lottery statutes. Federal parameters are refreshed annually when the IRS publishes projected tax-year thresholds.

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