GST Calculator
Calculate Goods and Services Tax (GST).
GST Details
₹
%
Itemized Tax Invoice Breakdown
| Particulars | Amount |
|---|
Total Amount (with GST)
₹11,800
Net Base Amount₹10,000
CGST (9%)₹900
SGST (9%)₹900
Total GST Amount₹1,800
GST Percentage18%
A Goods and Services Tax (GST) calculator computes the tax component included in or added to a transaction amount. It helps buyers, sellers, and service providers calculate tax values, net base costs, and total invoice amounts across different tax rates in India.
How the GST Calculator Works
The calculator processes four core input selections to determine tax breakdown amounts using exact mathematical formulas:
- Amount: The primary transaction figure entered into the calculator. The default starting amount is 10,000, which can be modified using the text input field or the range slider.
- GST Rate: The percentage rate applied to the transaction. You can select standard preset slabs of 0%, 5%, 12%, 18%, or 28%, or enter a custom rate up to 100% in the custom rate field. The default active rate is 18%.
- Calculation Type: A toggle to choose between two calculation options: Add GST (Exclusive) (applies when your starting amount excludes tax) and Remove GST (Inclusive) (applies when your starting amount already contains tax).
- Transaction Type: A dropdown selector specifying the geographic classification: Intra-State Sale (CGST + SGST) (splits tax equally into CGST and SGST) or Inter-State Sale (IGST) (assigns full tax to IGST).
GST Inclusive & Exclusive Formulas
Exclusive GST: Total GST = Base Amount × (GST Rate / 100) | Inclusive GST: Net Base Amount = Total Amount / (1 + GST Rate / 100)
For intra-state transactions, CGST = Total GST / 2 and SGST = Total GST / 2. For inter-state transactions, IGST = Total GST.
How to Use the Calculator
- Enter your transaction value in the Amount field or drag the slider.
- Select a rate slab (0%, 5%, 12%, 18%, 28%) or type a percentage in the Custom Rate % field.
- Click Add GST (Exclusive) if your amount excludes tax, or Remove GST (Inclusive) if your amount includes tax.
- Select your sale category from the Transaction Type dropdown: Intra-State Sale (CGST + SGST) or Inter-State Sale (IGST).
- Review the updated total amount, base price, tax breakdown figures, pie chart, and itemized invoice table.
Example Calculation (Worked Example)
Scenario: Transaction value of ₹10,000 at an 18% GST rate with Exclusive calculation and Intra-State transaction type.
Inputs
- Amount: ₹10,000
- GST Rate: 18%
- Calculation Type: Add GST (Exclusive)
- Transaction Type: Intra-State Sale (CGST + SGST)
Calculation
- Net Base Amount = ₹10,000
- Total GST (18%) = ₹10,000 × (18 / 100) = ₹1,800
- CGST (9%) = ₹1,800 / 2 = ₹900
- SGST (9%) = ₹1,800 / 2 = ₹900
- Gross Invoice Amount = ₹10,000 + ₹1,800 = ₹11,800
Result: Net Base Amount is ₹10,000, Total GST is ₹1,800 (split into ₹900 CGST and ₹900 SGST), and Gross Invoice Amount is ₹11,800.
Indian GST Rate Slabs & Product Matrix
Standard GST rate categories in India:
| GST Slab Rate | Product / Service Categories Covered | Intrastate Split (CGST + SGST) | Interstate IGST Rate |
|---|---|---|---|
| 0% (Nil Rated) | Unbranded food grains, fresh milk, vegetables, healthcare | 0% + 0% | 0% |
| 5% Slab | Packaged food items, footwear < ₹1,000, economy air travel | 2.5% + 2.5% | 5% |
| 12% Slab | Processed foods, business class air travel, computers | 6.0% + 6.0% | 12% |
| 18% Standard Slab | IT services, telecom, financial services, restaurants, consumer electronics | 9.0% + 9.0% | 18% |
| 28% De Merit Slab | Automobiles, luxury motorcycles, sin goods, aerated drinks | 14.0% + 14.0% | 28% |
Understanding Your Result
The calculator displays your calculation summary through key output metrics:
- Total Amount (with GST) / Gross Invoice Amount: The final transaction total including both net base cost and tax.
- Net Base Amount: The underlying cost before tax addition or after tax deduction.
- CGST (Central GST): Central government tax portion, set at half the total GST rate for intra-state sales.
- SGST (State GST): State government tax portion, set at half the total GST rate for intra-state sales.
- IGST (Integrated GST): Full tax amount shown when Inter-State Sale is selected.
- Total GST Amount: The combined tax value calculated for the transaction.
- GST Percentage: The effective tax rate applied to the computation.
When This Calculator Can Be Useful
- Preparing Quotations: Determine exact tax additions when creating price estimates for clients.
- Verifying Supplier Bills: Check whether tax values listed on incoming invoices match expected base figures.
- Determining Base Costs from Tag Prices: Calculate pre-tax costs for goods sold at tax-inclusive retail rates.
- Checking Tax Component Splits: Confirm how tax divides between CGST/SGST or IGST based on customer location.
Important Limitations
- Arithmetic Model Only: Computations rely strictly on numbers entered by the user; the tool does not determine which HSN code or tax rate legally applies to a product.
- Excludes ITC and Special Charges: The calculator does not account for Input Tax Credit (ITC), reverse charges, or compensation cess.
- Monetary Rounding: Output card figures and table rows round values to the nearest whole rupee.
Frequently Asked Questions
GST-exclusive calculation adds tax on top of a net base price. GST-inclusive calculation extracts embedded tax from a gross price to calculate the pre-tax base cost.
Select Inter-State Sale when goods or services cross state boundaries. In this mode, the calculator assigns the entire tax amount to IGST instead of splitting it into CGST and SGST.
Yes, you can enter any custom rate between 0% and 100% in the custom rate percentage input field.
For sales within the same state, tax regulations mandate splitting the total tax rate equally between the Central Government (CGST) and State Government (SGST).
No, the calculator computes figures based solely on the rate you enter or select. You must verify the applicable tax rate for your item separately.