GST Inclusive vs Exclusive: How to Work Out Both
By the Logicox team 3 min read
A price is GST exclusive when tax still has to be added on top, and GST inclusive when the tax is already inside it. Shops in India usually show inclusive prices to customers, while suppliers and freelancers often quote exclusive prices to businesses. Mixing the two up is the most common GST mistake, so here is how to handle each one.
Adding GST to an exclusive price
When the price is before tax, multiply to find the GST and add it on.
- GST = price × rate ÷ 100
- Total = price + GST, or in one step, price × (100 + rate) ÷ 100
Example: a service is quoted at ₹2,360 plus 18% GST. GST = 2,360 × 18 ÷ 100 = ₹424.80, so the invoice total is ₹2,784.80.
Removing GST from an inclusive price
When the tax is already inside the total, you cannot just take 18% of it. Divide instead.
- Price before GST = total × 100 ÷ (100 + rate)
- GST inside = total − price before GST, or total × rate ÷ (100 + rate)
Example: you paid ₹2,360 including 18% GST. Price before GST = 2,360 × 100 ÷ 118 = ₹2,000, so the GST inside is ₹360.
The mistake to avoid
Taking 18% of an inclusive total gives 2,360 × 18 ÷ 100 = ₹424.80, which is ₹64.80 too much. The tax was charged on ₹2,000, not on ₹2,360. The same trap catches people with discounts: removing 18% from ₹2,360 gives ₹1,935.20, not the ₹2,000 you started with.
| Rate | Add GST: multiply by | Remove GST: divide by | GST inside a total |
|---|---|---|---|
| 5% | 1.05 | 1.05 | total × 5 ÷ 105 |
| 18% | 1.18 | 1.18 | total × 18 ÷ 118 |
| 40% | 1.40 | 1.40 | total × 40 ÷ 140 |
CGST, SGST and IGST
On a sale within one state, the GST is split equally between central tax (CGST) and state tax (SGST). At 18%, the ₹360 above becomes ₹180 CGST and ₹180 SGST. A sale from one state to another carries the full ₹360 as integrated tax (IGST). The total is the same; only the lines on the invoice change.
Which rates apply now
Since 22 September 2025, most goods and services in India fall under two main rates, 5% and 18%, with 40% for a short list of luxury and sin goods. Many essentials are nil-rated. The old 12% and 28% slabs were folded into these, so bills from before that date may show rates that no longer apply. Always check the current rate for your item, because the GST Council can change it.
Do it with the calculator
In the GST Calculator, type the Amount, pick a rate from Quick GST rates or type your own in GST rate (%), then choose whether The amount is Before GST (add GST) or Including GST (remove GST). Under Show the tax as, pick CGST + SGST, IGST, or one total. One total also works for sales tax in Pakistan, which uses the same add and remove formulas.
For other percentage jobs, such as working out a discount before tax, the Percentage Calculator is quicker.
This guide explains the arithmetic only. For filing returns or claiming input tax credit, follow your accountant’s advice.