GST/Tax Calculator
Add or remove GST/tax from a price.
A GST/tax calculator adds tax to a price or extracts tax from a tax-inclusive price, showing the base amount, tax and total.
How to Use the GST/Tax Calculator
- Enter the amount. Type the base price or tax-inclusive total.
- Set the rate. Enter the tax percentage.
- Choose a mode. Add tax on top, or extract tax from an inclusive amount.
This tool processes your input locally in your browser. Nothing is uploaded.
What Is GST Calculator?
A GST/tax calculator helps you add tax to a base price or extract tax from an inclusive total, common for invoicing and pricing.
Two modes
"Add tax" calculates base × (1 + rate/100). "Tax included" reverses this: base = total / (1 + rate/100), and tax = total − base.
Key Features
- Add or extract tax
- Base, tax and total
- Transparent calculation
Examples
- 18% tax on $1,000 adds $180, total $1,180.
- From $1,180 inclusive, base is $1,000 and tax $180.
Common Use Cases
- Invoicing
- Pricing
- Accounting
Tips & Best Practices
- Use "tax included" when the shelf price already includes tax.
Limitations
- Uses a single flat rate; some regions have tiered or multiple rates.
Related Tools
Related Articles
Percentage Calculator – Complete Guide & Free Online Tool A percentage calculator solves common percentage problems: what is X% of Y, X is what percent of Y, increase or decrease by a percentage, and percentage difference — all with clear formulas. Free online tool included. Read guide → Percentage Change Calculator – Complete Guide & Free Online Tool A percentage change calculator measures how much a value increased or decreased as a percentage of its original value. Free online tool included. Read guide → Discount Calculator – Complete Guide & Free Online Tool A discount calculator tells you how much you save and the final price after applying a percentage discount to an item. Free online tool included. Read guide → Tip Calculator – Complete Guide & Free Online Tool A tip calculator computes the tip and total, and can split the amount evenly among any number of people. Free online tool included. Read guide →
Frequently Asked Questions
How do I add GST to a price?
Total = base × (1 + rate/100).
How do I extract tax from an inclusive price?
Base = total / (1 + rate/100); tax = total − base.
Is it free?
Yes, and it runs locally.