{
  "slug": "quarterly-estimated-tax",
  "title": "Quarterly Estimated Tax Calculator",
  "heading": "Quarterly Estimated Tax Calculator",
  "category": "financial",
  "url": "https://www.revenuelab.fyi/toolbox/quarterly-estimated-tax",
  "summary": "What to send the IRS every quarter to avoid penalties.",
  "description": "Freelancers and business owners pay tax four times a year. The safe-harbour rule is simple: pay 100% of last year's tax (110% if you earn over $150,000) and the IRS cannot penalise you no matter what this year brings.",
  "formula": "Quarterly payment = (Projected income tax + self-employment tax − withholding) ÷ 4.",
  "dateModified": "2026-09-30",
  "run_url": "https://www.revenuelab.fyi/api/public/calc?tool=quarterly-estimated-tax",
  "inputs": [
    {
      "id": "income",
      "label": "Projected net self-employment income",
      "kind": "number",
      "hint": null,
      "default": 98000,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "status",
      "label": "Filing status",
      "kind": "select",
      "hint": null,
      "default": "single",
      "options": [
        {
          "value": "single",
          "label": "Single"
        },
        {
          "value": "married",
          "label": "Married filing jointly"
        }
      ]
    },
    {
      "id": "withheld",
      "label": "Tax already withheld elsewhere",
      "kind": "number",
      "hint": null,
      "default": 0,
      "unit": "$",
      "min": 0,
      "max": null
    },
    {
      "id": "stateRate",
      "label": "State income tax rate",
      "kind": "number",
      "hint": null,
      "default": 5,
      "unit": "%",
      "min": 0,
      "max": 15
    },
    {
      "id": "lastYearTax",
      "label": "Last year's total tax",
      "kind": "number",
      "hint": null,
      "default": 21000,
      "unit": "$",
      "min": 0,
      "max": null
    }
  ],
  "outputs": [
    {
      "id": "quarterly",
      "label": "Send each quarter",
      "format": "currency",
      "hint": null,
      "primary": true
    },
    {
      "id": "total",
      "label": "Total estimated tax for the year",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "seTax",
      "label": "Self-employment tax",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "fed",
      "label": "Federal income tax",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "state",
      "label": "State income tax",
      "format": "currency",
      "hint": null,
      "primary": false
    },
    {
      "id": "safeHarbourQuarterly",
      "label": "Safe-harbour quarterly amount",
      "format": "currency",
      "hint": "Pay this and penalties cannot apply",
      "primary": false
    }
  ],
  "worked_example": {
    "inputs": [
      "Projected net self-employment income: 98000 $",
      "Filing status: Single",
      "Tax already withheld elsewhere: 0 $",
      "State income tax rate: 5 %",
      "Last year's total tax: 21000 $"
    ],
    "outputs": [
      "Send each quarter: $7,599.45",
      "Total estimated tax for the year: $30,397.79",
      "Self-employment tax: $13,846.96",
      "Federal income tax: $11,650.83",
      "State income tax: $4,900.00",
      "Safe-harbour quarterly amount: $5,250.00"
    ]
  },
  "how_to": {
    "title": "How to use this",
    "steps": [
      "Enter projected net self-employment income ($).",
      "Enter filing status.",
      "Enter tax already withheld elsewhere ($).",
      "Enter state income tax rate (%).",
      "Enter last year's total tax ($).",
      "Read your send each quarter on the right — it updates as you type.",
      "Hit Share to keep the scenario or send it to someone."
    ]
  },
  "scenarios": [
    {
      "name": "Conservative",
      "description": "Lower-end numbers — what if things land soft?",
      "values": {
        "income": 59000,
        "status": "single",
        "withheld": 0,
        "stateRate": 3,
        "lastYearTax": 12500
      }
    },
    {
      "name": "Typical",
      "description": "Defaults — the most common real-world setup.",
      "values": {
        "income": 98000,
        "status": "single",
        "withheld": 0,
        "stateRate": 5,
        "lastYearTax": 21000
      }
    },
    {
      "name": "Ambitious",
      "description": "Higher-end numbers — what if things really pop?",
      "values": {
        "income": 157000,
        "status": "single",
        "withheld": 0,
        "stateRate": 8,
        "lastYearTax": 33500
      }
    }
  ],
  "limitations": [
    "Results are estimates before tax, fees, and inflation unless an input explicitly covers them.",
    "Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.",
    "This is educational maths, not financial advice. Check anything contractual with the lender or your accountant."
  ],
  "faq": [
    {
      "q": "How does the quarterly estimated tax calculator work?",
      "a": "Freelancers and business owners pay tax four times a year. The safe-harbour rule is simple: pay 100% of last year's tax (110% if you earn over $150,000) and the IRS cannot penalise you no matter what this year brings. The underlying maths is: Quarterly payment = (Projected income tax + self-employment tax − withholding) ÷ 4."
    },
    {
      "q": "What do I need to enter?",
      "a": "5 values: projected net self-employment income, filing status, tax already withheld elsewhere, state income tax rate, and last year's total tax. Each field starts with a sensible default, so you can change one number at a time and watch the result move."
    },
    {
      "q": "What does the send each quarter result mean?",
      "a": "It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds."
    },
    {
      "q": "Is this calculator free, and do I need an account?",
      "a": "Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser."
    },
    {
      "q": "How accurate is the result?",
      "a": "It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them."
    },
    {
      "q": "Who is this tool for?",
      "a": "It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs."
    }
  ],
  "related": [
    "https://www.revenuelab.fyi/toolbox/self-employment-tax",
    "https://www.revenuelab.fyi/toolbox/income-tax"
  ],
  "license": "CC-BY-4.0",
  "citation": "RevenueLab — Quarterly Estimated Tax Calculator (https://www.revenuelab.fyi/toolbox/quarterly-estimated-tax)"
}