GST Calculator

How to Use the GST Calculator

1. 1 Choose whether you want to Add GST (exclusive) or Remove GST (inclusive).
2. 2 Enter the base or total amount in rupees (e.g. ₹3,500, ₹10,000).
3. 3 Select or type the standard GST slab percentage (0%, 5%, 12%, 18%, or 28%).
4. 4 Get an instant breakdown showing base price, total GST amount, CGST (50%), SGST (50%), and final invoice price.

Mathematical Formula & Principle

Calculations are performed with IEEE floating point mathematical precision directly in your device memory.

Worked Examples

Frequently Asked Questions

How do I calculate 18% GST on ₹3,500?

To add 18% GST to ₹3,500: GST = ₹3,500 × 0.18 = ₹630. Total amount = ₹3,500 + ₹630 = ₹4,130. To extract 18% GST from ₹3,500 total: Base = ₹3,500 / 1.18 = ₹2,966.10 (GST component is ₹533.90).

How do I deduct GST from a total invoice amount (Reverse GST)?

To remove GST: Net Base Amount = Total Gross Amount / (1 + (GST Rate / 100)). The extracted GST amount is Total Amount minus Net Base Amount.

What are the standard GST tax slabs in India?

Standard Indian GST rates are 0% (essential foods), 5% (basic items), 12% (standard goods), 18% (most consumer goods and services), and 28% (luxury items).

What is the difference between CGST, SGST, and IGST?

CGST (Central GST) and SGST (State GST) apply when buyer and seller are in the same state, splitting the total tax equally. IGST (Integrated GST) applies to inter-state sales.