The meaning of computed under section 158B to 158BG of the Income Tax Act is not defined in the act itself. But we can take guidance from decisions by various high courts. Here are excerpts of courts orders in which the Hon’ble High Court tried to explain the meaning of computed.
Meaning of computed defined by court
The phrase ‘computed’ used in section 158B to 158BG of the Income Tax Act came up before Hon’ble Kolkata High Court in CIT vs. Ashim Krishna Mondal  270 ITR 160 (Cal.) and it explained.
Meaning : The word ‘computation’ has not been defined in the act. The meaning of the word is to be gathered from the scheme of the act having regard to its ordinary grammatical meaning. The word ‘assessment’ has been defined to mean reassessment as well. Thus, one does not get the meaning from the act. Again one has to fall back on the ordinary grammatical meaning.
In order to give the meaning of the word ‘computation’, as intended by the legislature, one may note the interconnection, inter-dependence and interlacing of these two expressions for the purpose of the act in the context in which these are used. The act requires an assessment of the income of the assessee. For the purpose of assessment, the income is required to be computed. Upon such computation, in the process of assessment the income chargeable to tax is determined and assessed to tax.
Thus, in the context of the act, computation is a calculation, a method of determination by reckoning through calculation. It involves some methodical process with some amount of approximate mathematical precision based on the calculable data available.
Section 158B to 158BG of the Income Tax Act
158B. In this Chapter, unless the context otherwise requires,—
(a) “block period” means the period comprising previous years relevant to six assessment years preceding the previous year in which the search was conducted under section 132 or any requisition was made under section 132A and also includes the period up to the date of the commencement of such search or date of such requisition in the previous year in which the said search was conducted or requisition was made :
Provided that where the search is initiated or the requisition is made before the 1st day of June, 2001, the provisions of this clause shall have effect as if for the words “six assessment years”, the words “ten assessment years” had been substituted;
(b) “undisclosed income” includes any money, bullion, jewellery or other valuable article or thing or any income based on any entry in the books of account or other documents or transactions, where such money, bullion, jewellery, valuable article, thing, entry in the books of account or other document or transaction represents wholly or partly income or property which has not been or would not have been disclosed for the purposes of this Act, or any expense, deduction or allowance claimed under this Act which is found to be false.
In this article, you can get guidance from high courts on the meaning of computed under section 158B to 158BG of the Income Tax Act.
Updated up to Finance Act 2021