Estimates only — not financial, tax, or professional advice.
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What it calculates: Monthly TDS, Annual Tax Estimate, TDS Remaining.
Updated 5 June 2026 · Transparent assumptions
Salary TDS is an estimate that gets corrected as the year runs
An employer estimates your annual tax at the start of the year and deducts a twelfth each month. When the estimate changes — a raise, a bonus, a declared investment — the remaining liability is respread across the months left rather than recalculated from scratch.
That is why the monthly deduction jumps rather than drifting. A revision in month nine has only three months to absorb a full year’s correction.
Declare early, prove before the deadline
Deductions you declare at the start of the year reduce the estimated annual tax and therefore every monthly deduction. Declaring nothing and investing anyway means over-deduction all year and a refund claimed months later.
The catch is proof. Employers require documentary evidence before a cut-off, usually in the final quarter, and declarations without proof are reversed — which produces a very large deduction in the last month or two.
It sits on top of salary, so it attracts the highest band
Bonuses and incentives are added to salary income in the month received and taxed at your marginal rate, which is why the take-home on a bonus is so much lower than the gross suggests.
It also raises the annual estimate, so the months after a bonus often carry a higher regular deduction as well. Both effects are correct, and both surprise people who expected only the bonus itself to be taxed.
An employer estimate, not your final tax
This spreads whatever annual estimate you enter. It does not compute that estimate, which depends on your regime choice, exemptions, deductions and any other income you have.
Income outside salary — interest, capital gains, rent, freelance work — is usually not covered by salary TDS at all, and can leave a balance payable at filing along with interest for underpayment of advance tax.
Sources & References
Figures on this page are checked against primary, authoritative sources. Links open in a new tab.
Tax rules vary by country, state, tax year, filing status, income type, deductions, and exemptions. This calculator is educational and uses the values you enter. Always verify final tax treatment with official sources or a qualified tax professional.
Published the calculator with its formula, worked example, assumptions, limitations and a bespoke guide, and added an automated formula test suite covering it.
Tested the remaining annual liability spread across the months left, after crediting what has already been deducted.
Tested that tax already deducted beyond the full estimate leaves nothing further to collect rather than a negative deduction.
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