GST Calculation Formula
Expression: GST = Base × Rate/100 | Inclusive Base = Total / (1 + Rate/100)
For exclusive pricing, GST is added on base amount. For inclusive pricing, extract base by dividing total by (1 + rate). India uses 5%, 12%, 18%, and 28% slabs.
Example: 18% GST on ₹25,000
Base = ₹25,000, Rate = 18%
GST = 25,000 × 0.18 = ₹4,500
Result: Total = ₹29,500