The 'tax calculator' is an online computer-based programme hosted on the website of the tax department and is meant to help taxpayers or filers assess their tax liability.

The calculator works once a filer correctly feeds his basic details and information, as notified for the current assessment year by the government.

The e-filing facility for ITR-1 (for individuals having income from salaries, single house property and other sources) and ITR-4 (for individuals and Hindu Undivided Families (HUFs) having income from a proprietary business or profession) is expected to go online and get enabled this week itself.

The other ITRs will be hosted soon after, a senior IT department officer said. Last year, the e-filing commenced on July 1 as there was delay in finalisation of the ITR forms because of the controversy generated over a 14-page requiring assesses to disclose of bank account and foreign travel details.

Later the form was simplified and the number of pages was reduced to three. This year, the Central Board of Direct Taxes notified the new forms on March 30 and ITRs can be filed till the stipulated deadline of July 31.

At the time of filing the form, the taxpayer has to fill in his PAN, then personal information and information on taxes paid and TDS will be auto-filled in the form.

Officials said the calculator has been updated and calibrated by the department as per the new announcements made in respect of tax rates in the latest Budget.

The facility can be used by any taxpayer whether individual, corporate or any other entity, to compute their tax liability.

However, there is a word of caution from the tax department that filers should not solely rely on it as complicated cases of ITR have different requirements which may not be addressed by the 'calculator'.