Individuals (employees or sole proprietors) and companies are required to file annual income tax returns to the Inland Revenue Authority of Singapore (IRAS) and pay income tax at the prevailing Singapore corporate tax rate charged on chargeable income. The final IRAS tax rate will then be levied on the chargeable income which will work out the final tax amount payable to the tax authorities. IRAS has various income tax calculators and other tax calculators to assist companies in computing their final tax payable. 

Types of IRAS Tax Calculators

iras homepage with quick link to tax calculator list highlighted


IRAS has e-calculators on its website that are segregated by types of tax: Individual Income Tax, Corporate Tax, Withholding Tax, Property Tax and Goods and Services Tax. For example, individual tax residents can utilise the income tax calculator under Individual Income Tax to compute their tax liability. For property owners, there is a Property Tax Calculator that can compute their property tax liability where Annual Value input is keyed. With the key inputs on hand, companies and individuals can accurately determine their tax liabilities with the assistance of IRAS tax calculators.

IRAS Basic Corporate Tax Calculator (BTC)

screenshot of the iras tax calculator list page with the latest basic corporate tax calculators highlighted

Corporate tax calculator list on IRAS website


The Basic Corporate Tax Calculator is an excel workbook intended to help companies and tax agents prepare tax computations and tax schedules when filing their tax returns. It includes explanatory notes to guide taxpayers through their tax computations and validation checks against common errors. It is refreshed and updated for every YA, with the latest being the YA2019 workbook which is available for download on the IRAS website:
Basic Corporate Tax Calculator.

Companies can use the Basic Corporate Tax Calculator to assist companies to compute, on their own, the amount of corporate taxes they have to pay. The computation workings based on the Basic Corporate Tax Calculator can be presented in the tax computations worksheet as well which many companies have found useful in supporting their tax workings.

The Basic Corporate Tax Calculator is designed for trading companies. Trading companies usually have supporting tax schedules such as renovation, refurbishment and a capital allowance sheet. These schedules and templates are also included for reference in the latest YA2019 . It is important to note the BTC is not applicable to Investment Holding Companies.

Editing the Basic Corporate Tax Calculator

The BTC excel template contains various tab links related to different segments of the income tax returns. Under the “Tax Computation” tab is an overview of the tax adjustments.

iras basic tax calculator BTC tax computation tab with main fields highlighted

IRAS BTC excel file


Companies can input the relevant income and expenses figures into the yellow highlighted cells. Certain values, such as rental income, may require additional breakdown and analysis. Hence, the creation of the “Rental Income Schedule” where gross rent and various property-related expenses are required to be filled in.

Capital allowance usually would be the main deductible claims that are more complex for a typical company, and companies can utilise the 5 separate capital allowance schedule in the BTC template to derive their capital allowance claim for the relevant YA.

For more in-depth guidance and to ensure proper use of the BTC, consulting a qualified tax professional is recommended. Seeking professional assistance is a good option to ease your tax filing procedures, especially tax computations which may require detailed knowledge on IRAS and the Singapore Income Tax Act.

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