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Mathematics and Statistics · Ch 18 — Commercial Mathematics

GST and Basic Taxation

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GST and Basic Taxation

GST (Goods and Services Tax) is an indirect tax levied on the supply of goods and services in India. At Std XI level we handle its basic computation on a single transaction.

Taxable value, GST and invoice value

  • Taxable value — the price of the goods/services before tax (the base on which GST is charged).
  • GST at rate g%g\% is g100×taxable value\dfrac{g}{100}\times\text{taxable value}.
  • Invoice (total) value =taxable value+GST=taxable value(1+g100).=\text{taxable value}+\text{GST}=\text{taxable value}\left(1+\dfrac{g}{100}\right).

CGST, SGST and IGST

Note

How the GST rate is split

  • For a sale within the same state (intra-state), GST is split equally into CGST (Central) and SGST (State): each is g2%\dfrac{g}{2}\%. So 18%18\% GST =9%=9\% CGST +9%+9\% SGST.
  • For a sale between states (inter-state), the whole g%g\% is charged as a single IGST. The total tax collected is the same either way; only the split differs.
Tip

Working backwards from a tax-inclusive price …

Definition 1Taxable value

The pre-tax price of goods/services — the base on which GST at g%g\% is charged. Invoice value $=\text{taxable value}\left(1+ …

Definition 2CGST, SGST, IGST

Intra-state supply splits g%g\% into CGST g2%\tfrac{g}{2}\% + SGST g2%\tfrac{g}{2}\%; inter-state supply charges the full g%g\% as IGST. …

Definition 3Tax-inclusive reversal

From a GST-inclusive price, taxable value =invoice value1+g/100=\dfrac{\text{invoice value}}{1+g/100}; the GST is the difference. Do not subtra …