India GST & Reverse Tax Calculator

Select your calculation mode depending on whether you want to add GST to a net price or remove GST from a gross total invoice:

• •Forward GST Mode: Enter your base net price, choose the applicable GST slab (0%, 5%, 12%, 18%, or 28%), and toggle whether the supply is Intra-State (CGST + SGST) or Inter-State (IGST).
• •Reverse GST Mode: Enter your total inclusive invoice amount to extract the exact pre-tax base value and total GST paid.
• •Multi-Item Invoicing: Add multiple line items with different GST slabs to calculate comprehensive invoice totals and tax summaries.
• •Instant Export: Copy the calculated breakdown or export formatted invoice summaries for bookkeeping and accounting software.

GST calculations follow standard statutory arithmetic defined by the GST Council under the Central Goods and Services Tax Act 2017:

• •Intra-State Supply (Within Same State): The applicable GST is split exactly 50:50 into Central GST (CGST) and State GST / Union Territory GST (SGST/UTGST). For an 18% slab, 9% is CGST and 9% is SGST.
• •Inter-State Supply (Across State Borders / Exports): The entire tax percentage is levied as Integrated GST (IGST) and collected by the Central Government.
• •Reverse Tax Extraction: When extracting tax from an inclusive price (e.g. ₹1,18,000 at 18%), the formula Base = Gross / (1 + Rate/100) yields Base = ₹1,00,000 and Tax = ₹18,000.

Registered GST businesses can claim tax paid on business procurement as Input Tax Credit (ITC) to offset against output tax collected on sales. To ensure compliance, businesses must ensure suppliers file GSTR-1 on time so credits appear in GSTR-2B before claiming deductions.

• •Invoicing Requirements: Invoices must clearly show HSN/SAC codes, supplier GSTIN, recipient GSTIN, place of supply, and individual CGST/SGST/IGST breakdowns.
• •Composition Scheme: Eligible small taxpayers paying flat turnover tax (1% for manufacturers/traders, 5% for restaurants, 6% for service providers) cannot issue tax invoices or claim ITC.