GST Calculator

Add GST to a base price or pull GST out of an inclusive price — with the CGST/SGST split, live as you type.

Live — results appear as you type
Total with GST
Base Price
GST Amount
CGST (half)
SGST (half)

How GST Is Calculated

Adding GST (you know the pre-tax price): GST = Base × Rate ÷ 100, then Total = Base + GST. A ₹1,000 service at 18% becomes ₹1,180.

Removing GST (the price already includes tax): Base = Inclusive × 100 ÷ (100 + Rate). A ₹1,180 bill at 18% contains ₹180 GST on a ₹1,000 base. The common mistake is subtracting 18% of ₹1,180 (₹212.40) — that over-removes, because the 18% was charged on the base, not the total.

SlabTypical itemsCGST + SGST
5%Essentials, packaged food, transport2.5% + 2.5%
12%Processed food, some electronics6% + 6%
18%Most services & goods (most common)9% + 9%
28%Luxury goods, automobiles14% + 14%

Working out your margin after tax? Pair this with our Percentage Calculator or Discount Calculator.

Frequently Asked Questions

How do I calculate GST on a price?
To add GST: GST amount = Base × Rate ÷ 100, Total = Base + GST. ₹1,000 at 18% → ₹180 GST, ₹1,180 total.
How do I remove GST from an inclusive price?
Base = Inclusive × 100 ÷ (100 + Rate). ₹1,180 including 18% GST → ₹1,000 base + ₹180 GST. Use "Remove GST" mode above.
What are CGST and SGST?
For intra-state sales, GST splits equally: 18% = 9% CGST (central) + 9% SGST (state). Inter-state sales use IGST at the full rate.
What are the GST slab rates?
Main slabs: 5%, 12%, 18% (most common) and 28%. Some goods are 0%/exempt. Enter any custom rate above — the quick buttons cover the four main slabs.