The app can be downloaded for mobile phones and is available on the HMRC website.
In March’s Budget, the Government announced that 20m taxpayers would receive a personal tax statement from 2014/15.
HMRC research of over 2,000 people earlier this year found 57 per cent of taxpayers did not know how much income tax and National Insurance they paid.
While 70 per cent of people said they checked their bank statements regualarly, only 26 per cent said they similarly checked their tax statements.
Only 10 per cent of respondents could put an exact figure on how much tax they paid.
Despite this low engagement, 66 per cent said it was very or quite important that they could see how much tax they were paying on their payslip and 55 per cent were interested in a personal tax statement.
David Gauke, exchequer secretary to the Treasury, said: “We think it is right that people know how much tax they pay and what the Government spends it on.
“Our new tax calculator will allow them to find out, which is a big step towards a more transparent, 21st century system.”
The calculator can be found at http://www.hmrc.gov.uk/calcs-tools/index.shtml