Taxation · Income Tax Liability - Computation and Optimisation

Computation of Total Income and Tax Liability (Income-tax Act, 2025)

Updated 5 October 2026

Computation of total income means working out income under each of the five heads, adding clubbed income where the law requires, setting off and carrying forward losses, and then subtracting allowed deductions. Apply the slab rates to total income, add tax on special-rate income, subtract rebate, and add 4% cess.

Understand Computation of Total Income and Tax Liability

Tax is charged on total income of a tax year, not on your receipts. Total income is built in a fixed order. First you find income under each of five heads: salary, house property, profits and gains of business or profession, capital gains, and other sources. Each head has its own rules for what is taxable and which expenses are allowed.

Next you add income of other persons that the clubbing provisions make taxable in your hands, for example income from assets a person transferred to a spouse without adequate consideration. Then you set off losses. A loss is first set off within the same head, then against other heads, and what is left is carried forward. Some losses have restrictions on where they can be set off.

The result is gross total income. From it you subtract the deductions that the Act allows (savings, health insurance, donations and so on). What remains is total income, rounded as the law requires. Rates are then applied: normal slab rates on normal income, and special rates on items such as certain capital gains.

Finally you subtract rebate, add surcharge if income is high, and add health and education cess of 4%. For an individual you must also know which regime applies. The new regime is the default and allows only specified deductions. The old regime needs an option and allows the traditional deductions. Always read the question to see which regime is stated.

In the exam, this topic is mostly a presentation test. Marks come from the right head, the right set-off order and a clean computation statement.

Key rules to remember

Total income: Total income = Gross total income − Deductions allowed; Gross total income = Salary + House property + Business or profession + Capital gains + Other sources, after clubbing and loss set-off.
Order of working: Heads → Clubbing → Current-year set-off → Brought-forward loss set-off → Gross total income → Deductions → Total income; Brought-forward losses are set off after current-year losses and before deductions.
Tax liability: Tax = Tax on normal income at slab rates + Tax on special-rate income. Then deduct rebate, if eligible. Then add surcharge (with marginal relief) where income exceeds the surcharge threshold. Then add 4% cess on the total.; Rebate is available only if total income is up to the limit specified for the regime. Surcharge applies only at much higher incomes (above ₹50 lakh for an individual), so the two do not overlap. Surcharge is levied on the tax computed on income. Cess is 4% of tax plus surcharge. Marginal relief applies where income just crosses a surcharge threshold. Under the new regime it also applies where income just exceeds the rebate limit.
Capital loss set-off: Short-term capital loss: against short-term or long-term gains. Long-term capital loss: against long-term gains only; Capital losses cannot be set off against any other head. Unabsorbed capital loss is carried forward for 8 tax years, and only if the return is filed on or before the due date.
Loss restrictions: Speculation loss → speculation profit only. Specified business loss → specified business profit only. Non-speculation business loss → not against salary; In the current year, a non-speculation business loss can be set off against other heads except salary. This is separate from the rules for brought-forward losses. When carried forward, a non-speculative business loss is set off only against business profits, and a specified business loss only against specified business profit. A carried-forward house property loss can be set off only against house property income. A carried-forward capital loss can be set off only against capital gains.
Carry forward period: House property loss, non-speculative business loss and capital loss: 8 tax years. Speculation loss: 4 tax years. Specified business loss and unabsorbed depreciation: no time limit; Timely filing of the return (on or before the due date) is required to carry forward business loss, speculation loss, specified business loss and capital loss. House property loss and unabsorbed depreciation can be carried forward even if the return is filed late. A carried-forward house property loss is set off only against house property income, and a carried-forward capital loss only against capital gains.
Deduction ceiling: Total Chapter VI-A type deductions ≤ Gross total income (excluding specified special-rate capital gains and similar items on which the Act bars deduction); Deductions cannot create or increase a loss.

How to solve Computation of Total Income and Tax Liability questions

Use the same sequence for every question. It protects you from missing a step and lets the examiner award step marks.

1Read the question for residential status, tax year, age, and the regime (old or new). Decide which incomes are taxable in India.
2Compute income under each head separately, in the order salary, house property, business, capital gains, other sources. Show each head as a short working note.
3Add clubbed income under the correct head. Check each transfer: who transferred, to whom, and whether consideration was adequate.
4Set off current-year losses: within the same head first, then against other heads, keeping the restrictions (no business loss against salary, no speculation loss against other income, no capital loss against other heads).
5Set off brought-forward losses in the order the law allows. Note the amount that remains to be carried forward.
6Arrive at gross total income. Then deduct the allowed deductions, limited to what the regime permits and to the limits in the question.
7Round total income as required. Apply slab rates to normal income and special rates to special-rate income.
8Subtract rebate, add surcharge if applicable, add 4% cess, and state the tax payable. Write the loss to be carried forward below the computation.

Quickest way: Format-first method for the 70-mark written section and MCQs

When to use it: Use it for any comprehensive problem where time is short. Write the statement skeleton first, then fill in numbers.

Write the headings of the computation statement first: Salary, House property, Business, Capital gains, Other sources, Gross total income, Deductions, Total income, Tax.
Put each head's working in a small note below the statement, so the examiner can award step marks even if one figure is wrong.
Mark incomes that must not be added: exempt incomes, agricultural income and gifts that are not taxable. Mark incomes with special rates separately.
Write the loss set-off as a short table in words: loss, set off against, balance, carried forward.
Compute tax once, in slabs. Check the rebate eligibility before adding cess.
For MCQs, test one trap at a time: regime, clubbing condition, loss restriction or rebate eligibility. Eliminate options that break a rule. There is no negative marking, so always answer.

Common mistakes in Computation of Total Income and Tax Liability

Setting off business loss against salary income.
Students remember that inter-head set-off is allowed and forget the exceptions.
Fix: Keep a list of restrictions on a margin note: no business loss against salary, speculation loss only against speculation profit, capital loss only against capital gains.
Deducting savings, health insurance and donation deductions under the new regime.
The old regime format is practised more, so students apply it automatically.
Fix: Underline the regime in the question. The new regime allows only specified deductions, for example the standard deduction for salary, employer contribution to NPS and the deduction from family pension. Do not apply the old regime's savings, health insurance and donation deductions.
Setting off brought-forward loss after deductions, or before current-year loss.
Students treat all losses as one pool.
Fix: Current-year losses first, then brought-forward losses, both before gross total income. Deductions come after.
Clubbing income earned on the clubbed income itself.
Students assume everything connected to the transferred asset is clubbed.
Fix: Club only the income from the transferred asset. Income earned by the spouse on reinvesting that income is taxed in the spouse's hands.
Ignoring the rebate limit or applying it on income above the limit.
Students remember the rebate but not that it depends on total income and regime.
Fix: Check total income against the rebate limit of the regime given in the question before adding cess. Apply marginal relief where the question suggests it.
Forgetting to show the carry forward of unabsorbed loss.
Students stop once tax is computed.
Fix: Add a line at the end of the answer: loss to be carried forward, for how many years, and against which income it can be set off.

Worked examples

Example 1

Mr. Rao, a resident individual aged 35, opts for the old tax regime for the tax year 2026-27. Income from salary (computed) is ₹7,40,000. He has a self-occupied house with interest of ₹1,80,000 on a housing loan. Business income of the current year is ₹2,10,000, and he has a brought-forward business loss of ₹50,000 of an earlier year. Interest on savings and fixed deposits is ₹60,000. He invested ₹1,20,000 in eligible savings (life insurance and PPF; overall limit ₹1,50,000) and paid health insurance premium of ₹20,000 for himself by non-cash mode (limit ₹25,000 for a person below 60). Old regime slabs: up to ₹2,50,000 nil; ₹2,50,001 to ₹5,00,000 at 5%; ₹5,00,001 to ₹10,00,000 at 20%; above ₹10,00,000 at 30%. Rebate applies only if total income is up to ₹5,00,000. Compute total income and tax payable including 4% cess.

Show the solution

The old regime is available to an individual who opts for it, and this question states that option. The house property loss set-off and the deductions for savings and health insurance below are worked under the old regime only, as allowed by the Income-tax Act, 2025 for the tax year 2026-27. The slab rates and the rebate limit are used as given in the question.
Salary: ₹7,40,000 (given as computed).
House property: self-occupied, so only interest is claimed. The ₹2,00,000 cap on interest for a self-occupied house applies under the old regime. The interest of ₹1,80,000 is within that cap, so current-year loss = ₹1,80,000.
Business income of the current year: ₹2,10,000. Other sources: ₹60,000.
Step 1, current-year set-off: the house property loss of ₹1,80,000 is set off against the other heads. Salary ₹7,40,000 + business ₹2,10,000 + other sources ₹60,000 = ₹10,10,000. After set-off: ₹10,10,000 − ₹1,80,000 = ₹8,30,000.
Step 2, brought-forward set-off: the earlier-year business loss of ₹50,000 is set off against business income only. The ₹8,30,000 running total still includes the current-year business income of ₹2,10,000, so the ₹50,000 comes off this total once. Business income becomes ₹2,10,000 − ₹50,000 = ₹1,60,000. No brought-forward business loss remains.
Gross total income = ₹8,30,000 − ₹50,000 brought-forward business loss = ₹7,80,000. The loss is used only once, not again. Check by heads: salary ₹7,40,000 + business ₹1,60,000 + other sources ₹60,000 − house property loss ₹1,80,000 = ₹7,80,000.
Deductions: the old-regime deductions under the Income-tax Act, 2025 for life insurance and PPF investment and for health insurance premium are allowed up to the limits given in the question. Savings ₹1,20,000 (within the ₹1,50,000 limit) + health insurance ₹20,000 (within the ₹25,000 limit) = ₹1,40,000.
Total income = ₹7,80,000 − ₹1,40,000 = ₹6,40,000.
Tax: on first ₹2,50,000 nil. Next ₹2,50,000 at 5% = ₹12,500. Balance ₹1,40,000 at 20% = ₹28,000. Total = ₹40,500.
Rebate: not available as total income exceeds ₹5,00,000.
Cess at 4% of ₹40,500 = ₹1,620. Tax payable = ₹42,120.

Answer: Total income is ₹6,40,000 and tax payable (with cess) is ₹42,120.

Example 2

Mr. Arun, a resident individual, has salary income (after standard deduction) of ₹14,00,000 and interest on his own savings of ₹20,000 for the tax year 2026-27. He gifted ₹10,00,000 to his wife, who invested it in a bank fixed deposit and earned interest of ₹80,000 during the year. His wife also has her own salary of ₹3,00,000. Assume the new regime with these slabs: up to ₹4,00,000 nil; ₹4,00,001 to ₹8,00,000 at 5%; ₹8,00,001 to ₹12,00,000 at 10%; ₹12,00,001 to ₹16,00,000 at 15%; ₹16,00,001 to ₹20,00,000 at 20%; ₹20,00,001 to ₹24,00,000 at 25%; above ₹24,00,000 at 30%. No deductions are available. Rebate is available only if total income is up to ₹12,00,000. Compute Mr. Arun's total income and tax payable including 4% cess. Ignore surcharge.

Show the solution

Clubbing check: the clubbing provision of the Income-tax Act, 2025 applies when an individual transfers an asset to his or her spouse without adequate consideration. Mr. Arun transferred cash to his wife without adequate consideration, so income arising from that asset is clubbed in his hands. Only the income from the transferred cash is clubbed, not the cash gift itself. Interest of ₹80,000 is clubbed under other sources.
His wife's own salary of ₹3,00,000 arises from her own efforts, so it is not clubbed and stays in her hands.
Salary: ₹14,00,000.
Other sources: own interest ₹20,000 + clubbed interest ₹80,000 = ₹1,00,000.
Gross total income = ₹14,00,000 + ₹1,00,000 = ₹15,00,000. No deductions, so total income = ₹15,00,000.
Tax: ₹4,00,001 to ₹8,00,000 at 5% on ₹4,00,000 = ₹20,000. ₹8,00,001 to ₹12,00,000 at 10% on ₹4,00,000 = ₹40,000. ₹12,00,001 to ₹15,00,000 at 15% on ₹3,00,000 = ₹45,000. Total = ₹1,05,000.
Rebate: not available as total income exceeds ₹12,00,000.
Cess at 4% of ₹1,05,000 = ₹4,200. Tax payable = ₹1,09,200.

Answer: Total income is ₹15,00,000 and tax payable (with cess) is ₹1,09,200.

Exam tips

Write a computation statement with head-wise notes. Examiners award marks for each head even if the final tax is wrong.
Underline the regime, age and residential status in the question before you start. Most wrong answers come from using the wrong regime.
State the reason for every clubbing decision in one line: who transferred, to whom, and whether consideration was adequate.
In MCQs, check the loss restriction first. Questions often hide a speculation or capital loss that cannot be set off against other income.
End every answer with the loss to be carried forward and the number of years. It takes ten seconds and often carries a mark.

Practice questions from Income Tax Liability - Computation and Optimisation

Computation of Total Income and Tax Liability: frequently asked questions

What is the order of computing total income?

Compute income under the five heads, add clubbed income, set off current-year losses, then set off brought-forward losses to reach gross total income. Subtract deductions to get total income, then apply the tax rates.

Can a loss under one head be set off against another head?

Yes, in many cases, but with restrictions. Business loss cannot be set off against salary, speculation loss only against speculation profit, and capital loss only against capital gains. Check the rules for the specific loss and the regime given in the question.

Do deductions apply under the new tax regime?

The new regime allows only specified deductions, for example the standard deduction for salary, employer contribution to NPS and the deduction from family pension. Most savings and health deductions are for the old regime. Always read the question to see which regime applies.

Is cess charged before or after rebate?

Rebate reduces the tax first. Cess of 4% is then added on the tax after rebate (and after surcharge, if any). If the rebate wipes out the tax, no cess is payable.