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How to calculate GST in Excel and Google Sheets
Topic:Finance basicsExcel & Google Sheets
=A2*B2✓
Verified example
Computed by a real spreadsheet engine on the sample data below.
| Net Amount | GST Rate | GST Amount | Total |
| 1000 | 0.1 | ||
| 5000 | 0.18 | ||
| 250 | 0.05 | ||
| 800 | 0.15 |
=A2*B2→100
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Step by step
- 1Column A = Pre-tax Amount, Column B = GST Rate (e.g., 0.10 for 10%, 0.18 for 18%).
- 2GST amount: =A2*B2 in C2.
- 3Total including GST: =A2*(1+B2) in D2.
- 4To extract GST from a GST-inclusive price (reverse GST): =A2*B2/(1+B2).
- 5Round results: =ROUND(A2*B2,2).
Tips
- For India's GST with separate CGST and SGST, split the rate: if total GST is 18%, each component is 9%. Calculate each half separately for invoice display.
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Frequently asked
How do I calculate the pre-tax price from a GST-inclusive amount?
Divide by (1 + GST rate): =A2/(1+B2). For example, $110 at 10% GST gives $110/1.10 = $100.
What GST rate should I use?
Rates vary by country: Australia 10%, India 5%/12%/18%/28%, Canada 5%, New Zealand 15%.
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