How to calculate GST in India?

Multiply the original amount by the GST rate and divide by 100. For example, GST on Rs 1,000 at 18% = Rs 180. Total invoice = Rs 1,180. For CGST+SGST (intra-state): CGST = Rs 90, SGST = Rs 90.

What is the formula for reverse GST calculation?

Reverse GST formula: GST Amount = Total Price x Rate / (100 + Rate). Example on Rs 1,180 at 18%: GST = 1180 x 18/118 = Rs 180. Base price = Rs 1,000.

What are GST slab rates in India?

GST slabs: 0% for essentials (fresh produce, books), 5% for daily necessities (medicines, packaged food), 12% for computers and processed foods, 18% for electronics, mobile phones, restaurants and most services, 28% for luxury goods and cars.

What is the difference between CGST SGST and IGST?

CGST (Central GST) and SGST (State GST) are each half of the GST rate, applied on intra-state (same state) transactions. IGST (Integrated GST) is the full GST rate, applied on inter-state (different states) transactions.

What is GST inclusive calculation?

GST inclusive means the price already includes GST. Base Price = Total x 100 / (100 + GST Rate). For Rs 1,180 at 18%: base = Rs 1,000, GST = Rs 180.

How to calculate 18% GST?

18% GST on any amount: multiply by 0.18. On Rs 5,000: GST = Rs 900, Total = Rs 5,900. CGST = Rs 450, SGST = Rs 450 for intra-state.

Is this GST calculator free and accurate?

Yes. InvoPilot GST calculator is 100% free, no signup needed. Uses standard Indian GST formulas with exact CGST, SGST, IGST breakup for all slabs.

Free GST Calculator Online – Calculate GST Inclusive, Exclusive & Reverse | InvoPilot

🧮 Free · Instant · No Signup · India GST

Free GST Calculator Online
— India

Calculate GST exclusive, inclusive & reverse GST instantly. Full CGST, SGST & IGST breakup for all slabs — 5%, 12%, 18%, 28%. Free, accurate, no login needed.

✓ GST Exclusive ✓ GST Inclusive ✓ Reverse GST ✓ CGST + SGST ✓ IGST ✓ Bulk Calculator ✓ Copy Results

🔢

GST Calculator

GST Exclusive: Enter the base price before tax. GST will be added on top. E.g. Price ₹1,000. GST 18% = ₹180. Total = ₹1,180.

Original Amount (₹) — Before GST

Select GST Rate

Custom GST Rate (%)

% GST

Transaction Type

📊

Result

🧮

Enter an amount and click Calculate
to see your GST breakdown instantly.

GST Exclusive · 18% · CGST+SGST

Full Breakup

📦

Bulk GST Calculator — Multiple Items at Once

Calculate GST on multiple items simultaneously. Enter item details — taxable value and total with GST update automatically.

Item / Description	Unit Rate (₹)	Qty	GST %	Taxable Value	Total (incl. GST)

Taxable Value

₹ 0.00

Total GST

₹ 0.00

Grand Total

₹ 0.00

🛠️ How To Use

How to Use This GST Calculator

Calculate any GST amount in 4 steps — no formula, no spreadsheet needed.

Enter Amount

Type the price — base price (exclusive) or total with GST (inclusive/reverse).

Select GST Rate

Click a slab: 5%, 12%, 18%, 28% or type any custom rate.

Pick Mode

Exclusive (add GST), Inclusive (extract GST), or Reverse GST (find base).

Get Full Breakup

See CGST, SGST or IGST amounts, total invoice value. Copy with one click.

📐 Formulas

GST Calculation Formulas — India

All four standard GST formulas used by this calculator. Bookmark for quick reference.

GST Exclusive Add GST

GST = Price × Rate ÷ 100
Total = Price + GST Amount

Example: ₹1,000 × 18% = ₹180 GST
Total = ₹1,180
CGST = ₹90 | SGST = ₹90

GST Inclusive / Reverse Remove GST

GST = Total × Rate ÷ (100 + Rate)
Base = Total − GST Amount

Example: Total ₹1,180 at 18%
GST = 1180 × 18÷118 = ₹180
Base = ₹1,000

CGST + SGST (Intra-State)

CGST = GST Amount ÷ 2
SGST = GST Amount ÷ 2

Example: 18% GST on ₹1,000 = ₹180
CGST = ₹90 (Central Govt)
SGST = ₹90 (State Govt)

IGST (Inter-State)

IGST = Taxable Value × Rate ÷ 100

Example: 18% IGST on ₹1,000
IGST = ₹180 (full amount)
No CGST or SGST split

📋 GST Slabs

GST Rate Slabs in India

Current GST rates applicable in India for all major goods and services categories.

Rate	Category Examples	CGST	SGST
0%	Fresh vegetables, milk, eggs, books, newspapers	0%	0%
3%	Gold, silver, diamond jewellery	1.5%	1.5%
5%	Packaged food, medicines, rail tickets, edible oils	2.5%	2.5%
12%	Computers, processed food, butter, printing ink	6%	6%
18%	Mobile phones, AC, electronics, restaurants, IT services	9%	9%
28%	Luxury cars, cement, tobacco, aerated drinks	14%	14%

⚡ 18% Quick Reference

18% GST on Common Amounts

Instant reference for 18% GST (most common slab) on standard amounts.

Amount	GST 18%	CGST 9%	SGST 9%	Total
₹100	₹18	₹9	₹9	₹118
₹500	₹90	₹45	₹45	₹590
₹1,000	₹180	₹90	₹90	₹1,180
₹5,000	₹900	₹450	₹450	₹5,900
₹10,000	₹1,800	₹900	₹900	₹11,800
₹25,000	₹4,500	₹2,250	₹2,250	₹29,500
₹50,000	₹9,000	₹4,500	₹4,500	₹59,000
₹1,00,000	₹18,000	₹9,000	₹9,000	₹1,18,000

📖 Learn

What is GST? India’s Goods & Services Tax

GST (Goods and Services Tax) is India’s unified indirect tax system introduced on 1st July 2017. It replaced VAT, Service Tax, Excise Duty, and Entry Tax with one transparent national tax.

GST is applied at every stage of the supply chain. Businesses can claim Input Tax Credit (ITC) on GST paid on inputs, ensuring only the final consumer bears the full tax.

There are three types: CGST (Central), SGST (State) for intra-state transactions, and IGST (Integrated) for inter-state transactions.

Replaced VAT, Service Tax, Excise, CST — one nation, one tax
CGST + SGST for sales within the same state
IGST for sales across different states
Businesses above ₹20 lakh turnover must register for GST
Monthly/quarterly returns filed on GSTN portal (gst.gov.in)
Input Tax Credit reduces cascading tax burden for businesses

🔄 CGST vs SGST vs IGST

Tax	Full Form	When Applied	Revenue Goes To
CGST	Central GST	Intra-state sale	Central Govt
SGST	State GST	Intra-state sale	State Govt
IGST	Integrated GST	Inter-state sale	Centre (shared with destination state)
UTGST	Union Territory GST	Union Territory sale	Central Govt

Who Must Register for GST?

Businesses with turnover above ₹20 lakh (₹10 lakh in NE states)
All inter-state sellers regardless of turnover
E-commerce sellers and operators
Casual taxable persons and non-resident taxpayers
Reverse charge mechanism suppliers

❓ FAQ

Frequently Asked Questions about GST Calculator

Answers to the most common GST calculation questions in India.

Multiply the price by 18 and divide by 100. GST = Price × 18 ÷ 100. Example: 18% GST on ₹5,000 = ₹900. Total = ₹5,900. CGST = ₹450, SGST = ₹450. Use the calculator above — enter ₹5,000, select 18%, click Calculate.

Reverse GST finds the original price when the total (GST-included) price is known. Formula: GST = Total × Rate ÷ (100 + Rate). Example: ₹1,180 at 18% → GST = ₹1,180 × 18÷118 = ₹180. Base = ₹1,000. Select the “Reverse GST” tab above to calculate instantly.

GST on mobile phones is 18% (HSN code 8517). For intra-state: CGST 9% + SGST 9%. For inter-state: IGST 18%. Use our mobile bill format generator to create a complete GST mobile bill with IMEI and warranty details.

Select “GST Inclusive” mode. Formula: Base = Total × 100 ÷ (100 + Rate). Enter the total price, select rate, choose Inclusive — the calculator shows the base price and GST amount that was included in the total.

Most services in India attract 18% GST (IT, consulting, telecom, restaurants). Some are 5% (economy hotels, transport) or 12% (business airline tickets). Healthcare and education are generally exempt. Use SAC codes for services instead of HSN codes.

Use InvoPilot’s free billing software for PC — create a complete GST invoice with CGST/SGST/IGST, logo upload, HSN codes, discounts and PDF download. Free, no signup, works in any browser.

Yes. This calculator uses the standard GST formulas as per Indian GST law. All standard slabs (0%, 3%, 5%, 12%, 18%, 28%) are supported along with any custom rate. It provides exact CGST, SGST, and IGST breakup for both intra-state and inter-state transactions.

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