What Is Taxable Income?
This calculator applies to US federal income tax for the 2026 tax year. Taxable income is the portion of your income that is actually subject to federal income tax. It is found by taking your Adjusted Gross Income (AGI) and subtracting your deductions: either the standard deduction or your itemized deductions (whichever is larger), plus the Qualified Business Income (QBI) deduction if you qualify.
How to Use It
Enter your AGI (found on your Form 1040), choose your filing status, and enter any itemized deductions. If your itemized total is less than the standard deduction, the calculator automatically uses the larger standard deduction. Add your QBI deduction if you have pass-through business income. The result is your estimated federal taxable income.
The Formula Explained
The equation is
Worked Example
Suppose a single filer has an AGI of 80,000, itemized deductions of10,000, and no QBI. The standard deduction (16,100) exceeds the itemized amount, so the calculator uses16,100.
使用注意事項與精準校對原則（6 大核心守則）
📐 1. 嚴格對齊輸入量綱與單位
輸入各項數值時請務必確認量綱（例如小時、天數、金額、百分比），避免單位不匹配引發推算偏差。
🔒 2. 純前端本機毫秒級隱私保障
所有計算邏輯 100% 在您的終端瀏覽器內完成，資料絕不上傳伺服器，嚴格守護商業與個人隱私。
📊 3. 符合公認學術與產業計算模型
演算法嚴格遵循國際通用數學公式與標準計算模型，經多重情境交叉核對，數值嚴密精確。
📋 4. 一鍵複製與免登入 PDF 匯出
支援一鍵複製推算結果字串至剪貼簿，亦可直接點擊列印按鈕輸出純淨 PDF 工作報表。
🔄 5. 多情景敏感度動態對比
建議針對極端值與多組預期情景分別試算，觀察輸出數據的波動區間，輔助做出更穩健的決策。
🛡️ 6. 專業諮詢與日常參考免責聲明
本工具運算結果供日常排程、學業研習與事前參考之用，如涉及重大法規或投資決策請諮詢持證專家。