Complete guide
Reviewed July 2026Income tax feels opaque because most people misunderstand one thing: slabs are progressive, not a single flat rate. You never pay your top-slab rate on your whole income — each slice of income is taxed at its own rate. Understanding this removes the fear of 'jumping a bracket' and makes your real tax bill predictable.
This calculator estimates your income tax under the new regime — now the default — applying the current slabs, the standard deduction, the Section 87A rebate that makes modest incomes tax-free, and the 4% health-and-education cess on top. It returns your total tax and your take-home income.
Below: how progressive slabs actually work (with a diagram), worked examples, the rebate that surprises people, old-vs-new regime guidance, and the mistakes that lead to wrong estimates. Tax rules change with each Budget, so treat this as an estimate and verify current provisions.
How progressive slabs work
Your income is divided into bands. The first band is taxed at 0%, the next at 5%, the next at 10%, and so on. Only the income that falls inside each band is taxed at that band's rate — so earning one rupee more never reduces your take-home.
The calculation, step by step
1. Taxable income = Gross − standard deduction 2. Tax = sum over slabs of (income in slab × slab rate) 3. Apply Section 87A rebate if eligible (can zero out the tax) 4. Add 4% health & education cess on the tax 5. Take-home = Gross − (tax + cess)
Worked example
- Gross salary ₹12,00,000; apply the standard deduction to get taxable income.
- Tax is computed slab by slab — the 0% band pays nothing, then each higher slice at its rate.
- The result is the base tax; the Section 87A rebate applies only up to the eligibility ceiling, so at ₹12 lakh it doesn't zero the bill.
- Add 4% cess: e.g. base tax ₹71,500 → cess ₹2,860 → total ₹74,360.
- Take-home = 12,00,000 − 74,360 = ₹11,25,640 (before EPF and professional tax).
New regime vs old regime
The choice hinges on your deductions. If you fully use 80C (₹1.5 lakh), 80D, HRA and a home-loan interest deduction, the old regime can win despite higher rates. If you have few deductions, the new regime's lower rates usually win — and it's simpler. Compute both before filing; the calculator here uses the new regime as the default baseline.
| Feature | New regime (default) | Old regime |
|---|---|---|
| Slab rates | Lower, more slabs | Higher, fewer slabs |
| Standard deduction | Available | Available |
| 80C, 80D, HRA, home-loan interest | Mostly not available | Available |
| Best for | Few deductions / simplicity | Large deductions (80C + HRA + home loan) |
| Default | Yes (opt out to use old) | No (must opt in) |
Using this calculator and avoiding mistakes
- Enter your gross annual income (salary plus other taxable income).
- Read the total tax + cess and your estimated take-home.
- If you have significant deductions, also compute the old regime separately and compare — pick the lower total.
- Remember this is an estimate: it excludes EPF, professional tax, surcharge on very high incomes, and income-specific exemptions.
Common mistakes
- Thinking a raise that crosses a slab reduces take-home — it never does; only the extra rupees are taxed higher.
- Forgetting the 4% cess, which adds to every non-zero tax bill.
- Assuming the 87A rebate applies at any income — it cuts off at an eligibility ceiling; above it, normal tax applies.
- Comparing regimes on rates alone, ignoring the deductions the old regime allows.
- Confusing gross with taxable income — the standard deduction and (in old regime) other deductions reduce the taxed amount.
Frequently asked questions
Glossary
- Progressive tax
- A system where higher income bands are taxed at higher rates, band by band.
- Tax slab
- An income band with its own tax rate (0%, 5%, 10%, ...).
- Taxable income
- Gross income minus the standard deduction and any eligible deductions.
- Section 87A rebate
- A rebate zeroing tax for incomes up to an eligibility ceiling under the new regime.
- Cess
- A 4% health-and-education levy charged on the tax amount.
- Standard deduction
- A flat, no-proof deduction from salary income available in both regimes.
- New regime
- The default tax structure with lower rates but few exemptions.
- Effective tax rate
- Total tax divided by total income; always lower than your top slab rate.
Key takeaways
Income tax is progressive: each slice of income pays its own slab rate, so your effective rate is always below your top rate and a raise never cuts take-home. Compute taxable income (gross minus standard deduction), apply the slabs, use the 87A rebate if eligible, add 4% cess. Choose the new regime for simplicity and few deductions, and the old regime when large 80C/HRA/home-loan deductions win. Always compare both before filing.
Enter your gross income above for your estimated tax and take-home; if you have big deductions, compare against the old regime before you file.