How Income Tax Actually Works on Your Salary in AY 2026-27
Comparing both regimes can help explain differences in estimated liability. This calculator computes a side-by-side estimate for AY 2026-27 (FY 2025-26) using the period-specific rules shown on this page.
The choice between the Old and New Tax Regime depends almost entirely on how much you can legitimately deduct each year. The New Regime offers lower slab rates and a higher tax-free threshold (effectively ₹12 lakh via the Section 87A rebate), but strips away nearly every deduction — no 80C, no HRA exemption, no Section 24 home loan interest benefit. The Old Regime keeps all these deductions intact but taxes you at higher marginal rates.
A Worked Example
Take a salaried employee earning ₹15,00,000 annually with ₹1,50,000 in 80C investments (PPF + ELSS), ₹50,000 in NPS under 80CCD(1B), and ₹2,40,000 in home loan interest under Section 24. Under the Old Regime, after the ₹50,000 standard deduction and these deductions, taxable income drops to roughly ₹10,10,000 — bringing tax down meaningfully from the headline slab rate. Under the New Regime, the same ₹15,00,000 only gets the flat ₹75,000 standard deduction, leaving taxable income at ₹14,25,000 with none of those investment-linked deductions counted. For this specific profile, the Old Regime usually shows a difference of a noticeable margin — but change the home loan interest to zero (no home loan) and the answer often flips to the New Regime.
Common Mistakes That Cost Real Money
The most expensive mistake is sticking with whatever regime your employer defaulted you into without checking the comparison yourself — employers often default to the New Regime since it requires less paperwork on their end, even when the Old Regime would save you more. The second common error is forgetting that the standard deduction amounts differ between regimes (₹50,000 Old vs ₹75,000 New) — using the wrong figure throws off every downstream calculation. A third frequent oversight: forgetting that HRA exemption is only available under the Old Regime, which alone can shift the comparison dramatically for anyone paying significant rent in a metro city.
When the Old Regime Has the Lower Modeled Tax
As a rule of thumb, if your total annual deductions (80C + 80D + HRA exemption + home loan interest + NPS 80CCD(1B)) exceed roughly ₹4 to 4.5 lakh, the Old Regime typically results in lower tax. This threshold is highest for salaried employees with an active home loan and full 80C utilization, and lowest for those with no investments and no home loan — for whom the New Regime often shows lower modeled tax.
What This Calculator Does Differently
Unlike a simple slab-rate lookup, this tool applies the Section 87A rebate correctly under the New Regime (zero tax up to ₹12 lakh for most salaried taxpayers, not just a slab calculation), applies the ₹75,000 New Regime and ₹50,000 Old Regime standard deductions for eligible salaried taxpayers, and includes the 4% Health and Education Cess on the final tax figure — a step many basic calculators skip, leading to numbers that look lower than your actual liability.