How to Use the Income Tax Calculator
Enter your annual income and select your age group. The calculator shows tax under both new and old regimes side by side. For the old regime, optionally enter deductions (80C, 80D, HRA, home loan interest). The recommended regime is highlighted.
Income Tax Calculator Formula
Tax = slab_rate × (income − slab_start) + tax_on_lower_slabs; Cess = Tax × 4%New regime= 0–4L:0%, 4–8L:5%, 8–12L:10%, 12–16L:15%, 16–20L:20%, 20–24L:25%, >24L:30%Old regime= 0–2.5L:0%, 2.5–5L:5%, 5–10L:20%, >10L:30%87A rebate= Zero tax if total income ≤ ₹12L (new) or ≤ ₹7L (old)
Example Calculation
Annual income ₹15 lakh, new regime:
4L@0% + 4L@5% + 4L@10% + 3L@15% = 0 + 20,000 + 40,000 + 45,000 = ₹1,05,000; Cess = ₹4,200
Total tax = ₹1,09,200; Effective rate ≈ 7.3%; Monthly TDS ≈ ₹9,100
How Income Tax Is Actually Calculated
Indian income tax is slab-based, which is widely misunderstood. Your entire income is not taxed at a single rate. Instead, each band of income is taxed at its own rate, and only the portion that falls inside a higher band is taxed at the higher rate. This is why your effective tax rate — total tax divided by total income — is always lower than your top slab rate.
For example, at ₹15 lakh income under the new regime, the effective rate works out to roughly 7.3%, even though the top slab touching that income is far higher. The calculator above applies the slabs for you, but understanding the mechanism stops the common panic that "crossing into the next slab" will tax all your income more — it never does.
The Two Regimes Side by Side
India runs two systems. The new regime (now the default) has lower rates but removes almost all deductions and exemptions. The old regime has higher rates but lets you reduce taxable income through 80C, 80D, HRA, home-loan interest, and more.
- New regime: zero tax up to ₹12 lakh total income (via the enhanced Section 87A rebate), plus a ₹75,000 standard deduction for the salaried. Simple, no proofs needed.
- Old regime: higher slab rates, but worth it if your total deductions exceed roughly ₹3.75 lakh.
- You can switch regimes year to year if you are salaried, so re-evaluate every filing season.
The 87A Rebate Explained
The Section 87A rebate is what makes income up to ₹12 lakh tax-free under the new regime — a frequent point of confusion. It does not change the slabs; rather, after your tax is computed normally, the rebate wipes out the liability entirely if your total income stays within the limit. The catch is the cliff: earn even slightly above the threshold and the rebate no longer applies, so the tax can jump sharply. If your income is hovering just above ₹12 lakh, legitimate deductions (or timing a bonus) can sometimes bring you under the limit and save a disproportionate amount of tax.
Legitimate Ways to Lower Your Tax
If the old regime suits you, the main levers are well established. Section 80C (up to ₹1.5 lakh) covers EPF, PPF, ELSS funds, life insurance, and home-loan principal. Section 80D covers health insurance premiums. HRA exemption helps if you pay rent in a city. An additional ₹50,000 is available for NPS under 80CCD(1B). Stacking these is how salaried taxpayers push total deductions past the break-even point that makes the old regime cheaper. Whatever you do, decide based on a side-by-side calculation rather than a rule of thumb — the right answer is specific to your salary and spending.
Frequently Asked Questions
What is the zero tax income limit under the new regime in FY 2025-26?
Under the new tax regime (IT Act 2025), individuals with total income up to ₹12 lakh pay zero income tax due to the enhanced rebate under Section 87A of ₹60,000.
Which is better — new or old tax regime?
The new regime is better if your deductions (80C, HRA, home loan interest, etc.) are less than approximately ₹3.75 lakh. If you have higher deductions, the old regime saves more tax.
Is standard deduction available in the new tax regime?
Yes. A standard deduction of ₹75,000 is available for salaried employees under the new regime from FY 2024-25 onwards.
Sources
All calculations run in your browser and are provided for information only — they are not investment, tax or legal advice. Verify current rates and rules with the official source above before acting.
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