Progressive tax (custom brackets) API

Computes progressive tax via the marginal-slice method over CALLER-SUPPLIED brackets (no embedded rate tables), returning per-bracket breakdown plus marginal and effective rates. Answers 'What tax do these brackets produce?', 'What is my effective vs marginal rate?'.

Price$0.06per request

MethodPOST

Route/v1/finance/progressive-tax

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

taxprogressivebracketsmarginal-rateeffective-rateincome-taxaccountingcustom

API URLhttps://x402.hexl.dev/v1/finance/progressive-tax

Integration docs

Example request

{
  "income": 80000,
  "brackets": [
    {
      "upTo": 20000,
      "rate": 0.1
    },
    {
      "upTo": 50000,
      "rate": 0.2
    },
    {
      "rate": 0.3
    }
  ],
  "deduction": 10000
}

Example response

{
  "income": 80000,
  "deduction": 10000,
  "taxableIncome": 70000,
  "totalTax": 14000,
  "afterTaxIncome": 66000,
  "marginalRate": 0.3,
  "marginalPercent": 30,
  "effectiveRateOnTaxable": 0.2,
  "effectiveRateOnGross": 0.175,
  "effectivePercentOnGross": 17.5,
  "bracketBreakdown": [
    {
      "from": 0,
      "to": 20000,
      "rate": 0.1,
      "taxableInBracket": 20000,
      "tax": 2000
    },
    {
      "from": 20000,
      "to": 50000,
      "rate": 0.2,
      "taxableInBracket": 30000,
      "tax": 6000
    },
    {
      "from": 50000,
      "to": 70000,
      "rate": 0.3,
      "taxableInBracket": 20000,
      "tax": 6000
    }
  ],
  "interpretation": "Top dollar taxed at 30% (marginal); overall 17.5% of gross income paid in tax (effective)."
}

Input schema

{
  "type": "object",
  "required": [
    "income",
    "brackets"
  ],
  "properties": {
    "income": {
      "type": "number",
      "examples": [
        80000
      ]
    },
    "brackets": {
      "type": "array",
      "items": {
        "type": "object"
      },
      "examples": [
        [
          {
            "upTo": 20000,
            "rate": 0.1
          },
          {
            "upTo": 50000,
            "rate": 0.2
          },
          {
            "rate": 0.3
          }
        ]
      ]
    },
    "deduction": {
      "type": "number",
      "examples": [
        10000
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}