Add GST vs Remove GST — what's the difference?
"Add GST" starts from a base price and calculates the tax on top (base × rate ÷ 100), giving you the final price a customer pays. "Remove GST" works backwards from a GST-inclusive price to find the original base amount — useful when a price tag or invoice already includes tax and you need to know the pre-tax value.
Common GST rate slabs
Most goods and services fall into a small number of standard rate slabs (commonly 5%, 12%, 18%, and 28% in South Asian GST systems), with essential items often taxed at 0% or a reduced rate, and luxury or sin goods at the highest slab.
Formula for removing GST
Base amount = Total ÷ (1 + rate÷100). For example, a GST-inclusive price of 1,180 at 18% GST: base = 1,180 ÷ 1.18 = 1,000.
Frequently asked questions
Is GST the same as sales tax? They're similar in concept (both are consumption taxes) but differ in structure — GST is typically a multi-stage value-added tax with input credits, while sales tax is usually a single-stage tax at the point of final sale.
Do all products have the same GST rate? No, rates vary by product/service category — always check the applicable slab for your specific item before invoicing.