GST formulas
- Add GST: Total = Price + Price x Rate/100
- Remove GST: Price = Total / (1 + Rate/100)
GST slab rates at a glance
| Slab | Typical items | Rs.1,000 becomes |
|---|---|---|
| 5% | Essentials, packaged food | Rs.1,050 |
| 12% | Processed goods, mobiles | Rs.1,120 |
| 18% | Most services, electronics | Rs.1,180 |
| 28% | Luxury, cars, tobacco | Rs.1,280 |
Discount first, then GST
Shops apply the discount on MRP, then GST on the reduced price. Example: Rs.2,000 shoes at 10% off = Rs.1,800, plus 18% GST = Rs.2,124 total. Use the Discount Calculator for step one, then the GST Calculator for step two.
Worked examples
- Rs.1,000 + 18% GST = Rs.1,180
- Rs.1,180 inclusive of 18% = Rs.1,000 base
- Rs.500 + 5% GST = Rs.525
Related tools
- GST Calculator — add and remove GST instantly.
- Percentage Calculator — any percent math.
- Discount Calculator — sale price before GST.
Frequently Asked Questions
How do I calculate GST?
GST Amount = Price x (Rate / 100). Total = Price + GST Amount. Enter both in the free GST calculator for instant results.
How do I remove GST from a price?
Price = Total / (1 + Rate/100). E.g. Rs.1,180 at 18% = 1180/1.18 = Rs.1,000 base price.
What are the GST slabs in India?
0%, 5%, 12%, 18% and 28%. Essentials are 0-5%, most goods and services 12-18%, luxury and sin goods 28%.
How do I add 18% GST to Rs.1,000?
GST = 1000 x 0.18 = Rs.180. Total = Rs.1,180. The calculator does this in one click.
Is GST applied before or after discount?
Discount first, then GST on the discounted price. Calculate the sale price with the Discount Calculator, then add GST.
What is the difference between CGST, SGST and IGST?
CGST + SGST apply to intra-state sales (split equally); IGST applies to inter-state sales. The total rate is the same — only the split differs.