How to Calculate Income Tax on Salary: A Step-by-Step Guide With Examples

Working out your income tax doesn’t have to feel like guesswork. For Tax Year 2026-27, the process boils down to this: take your gross salary, subtract the ₹75,000 standard deduction, run the balance through the new-regime slabs, knock off any rebate you qualify for, and finally add 4% cess. If your salary falls at or under ₹12.75 lakh, chances are you won’t owe anything at all. This article walks through each step with real figures, worked-out examples, and the slip-ups people commonly make along the way.

How Is Income Tax Calculated on Salary for Tax Year 2026-27?

There’s a set sequence to follow here. Tax Year 2026-27 runs from 1 April 2026 through 31 March 2027, and unless you actively opt for the old regime, the new one applies by default.

• Gross salary: Start with everything — basic pay, allowances, bonuses — before any deductions or tax come off the top.
• Standard deduction: Subtract ₹75,000 if you’re under the new regime (₹50,000 under the old one) to arrive at your taxable income.
• Slab tax: Each slab rate only touches the income sitting inside that particular band. Add up what each band contributes.
• Rebate: If your taxable income qualifies, Section 156 trims the slab tax down — sometimes all the way to zero.
• Cess: Finally, tack on 4% health and education cess to whatever tax remains after the rebate. That’s your estimated tax.

What Are the New Regime Income Tax Slabs for Tax Year 2026-27?

The default slabs come from Section 102 of the Income-tax Act, 2025. One thing worth remembering: each rate only applies to the slice of income within its own band — never to the entire amount.

• Up to ₹4,00,000: The first four lakh is tax-free, full stop.
• ₹4,00,001 to ₹12,00,000: This stretch gets taxed at 5% in the lower half and 10% in the upper half.
• ₹12,00,001 to ₹24,00,000: Three ₹4-lakh bands follow, taxed at 15%, 20%, and 25% respectively.
• Above ₹24,00,000: Anything beyond this point is taxed flat at 30% — there’s no higher band waiting after that.

How Do the Rebate and Marginal Relief Change the Final Tax?

Section 156 offers resident individuals a rebate worth up to ₹60,000, provided taxable income doesn’t cross ₹12 lakh. Step just a bit over that line, though, and marginal relief thrown in to stop the tax bill from outpacing the extra income earned.

• Full rebate: If taxable income sits at or below ₹12,00,000, you get either 100% of the tax wiped out or ₹60,000 off — whichever turns out smaller.
• Marginal relief: Earn a little more than ₹12 lakh, and your tax gets capped at just the amount by which you’ve crossed that threshold.
• Zero-tax salary: Here’s a neat number — a gross salary of ₹12.75 lakh, once you remove the ₹75,000 standard deduction, lands exactly at ₹12 lakh taxable income. That means the rebate wipes the tax out entirely.

How Much Tax Is Payable on an ₹18 Lakh Salary? (Worked Example)

Let’s take a salaried individual earning ₹18 lakh gross, with no other income and no deductions beyond the standard one. Here’s how the new-regime math plays out.

• Taxable Income: ₹18,00,000 minus ₹75,000 leaves ₹17,25,000 — which pushes into the 20% slab.
• Slab tax: Breaking it down — ₹20,000 from the 5% band, ₹80,000 from the 10% band, ₹60,000 from the 15% band, and ₹25,000 for the portion above ₹16 lakh.
• Rebate: None applies here, since taxable income is well past ₹12 lakh. So the slab tax stands at ₹1,45,000.
• Cess: Add 4% of that, which comes to ₹5,800, bringing the total estimated tax to ₹1,50,800.
• Old-regime comparison: Under the old regime, with just the ₹50,000 deduction, the same salary would cost roughly ₹3,51,000 — a difference of about ₹2,00,200.

How Much Income Tax Do Common Salaries Attract?

Here’s a quick look at estimated tax across five salary levels under the new regime, worked out slab by slab.

These numbers assume a resident below 60, salary as the sole income source, the standard deduction applied, and no surcharge. One thing that stands out — at ₹13.05 lakh, marginal relief keeps the tax pinned at just ₹31,200, well under what a straightforward slab calculation might suggest.

Does the Old Tax Regime Change How Salary Tax Is Calculated?

The overall method is unchanged — what differs is the input. Those who stick with the old regime work with tighter exemption limits, but they also get access to a wider range of deductions. Which one actually works out better really comes down to what you can claim.

• Slabs: Residents under 60 pay nothing up to ₹2,50,000, after which rates climb to 5%, 20%, and 30%.
• Deduction: The standard deduction here is ₹50,000, and other eligible exemptions get subtracted before the slabs are applied.
• Rebate: The old regime caps its rebate at ₹12,500, and only for taxable income up to ₹5,00,000.

What Do Salaried Taxpayers Most Often Ask About Salary Tax?

A few quick answers can help you gauge where you stand before diving into the full calculation. These all assume a resident individual with salary as the only source of income.

• ₹12 lakh salary: No tax owed — taxable income here works out to ₹11,25,000, which falls comfortably within the full Section 156 rebate.
• Salary above ₹12.75 lakh: Tax does apply, though marginal relief softens the blow for amounts just over the line.
• Tax already deducted: Your employer is already withholding tax through the year, so match your own estimate against Form 16 before you file.

Which Mistakes Make Salary Tax Calculations Go Wrong?

Most errors aren’t dramatic — they’re small oversights that pile up across the steps. A quick check on each can save you from a miscalculated estimate.

• Wrong slabs: Relying on older slab structures or outdated Section 87A references won’t match what Tax Year 2026-27 actually requires.
• One rate for everything: Applying a single rate across the full taxable income inflates the tax owed — remember, each rate only covers its own slice.
• Skipping the standard deduction: Forgetting the ₹75,000 deduction changes your taxable income and could unnecessarily push you past the ₹12 lakh mark.
• Ignoring cess: Leaving out the 4% cess means underestimating your final tax — and that gap only grows as income increases.
• Treating estimates as final: Remember, what’s actually deducted at source and reflected in Form 16 is what determines your real balance — whether payable or refundable.

Why Should Salaried Taxpayers Estimate Their Tax Early?

Getting ahead of your tax estimate turns a potential surprise into a manageable plan. Take someone earning ₹18 lakh — the gap between regimes here exceeds ₹2 lakh before deductions even come into play, so the choice genuinely matters. Use an income tax calculator 2026-27  that lets you compare both regimes side by side using the same inputs.

• Planning ahead: Knowing your likely tax liability in advance means you can set aside funds and plan savings well before the year wraps up.
• Choosing a regime: Running the same income through both regimes makes it obvious which one actually benefits you based on your real deductions.
• Avoiding mismatches: Cross-checking your estimate against Form 16 early helps you catch discrepancies before — not after — you’ve filed.

Conclusion

Tax rules shift from year to year, and even a small oversight can cost real money. That is why this article will help salaried taxpayers looking for clearer tax estimates, smarter savings plans, and dependable life cover can reach out and take the next step with confidence.