GST / VAT Calculator
Add GST/VAT to a price or remove it from a tax-inclusive price. Mode: 1 = add tax, 2 = remove tax
Interactive Sandbox
Adjust values in real-time and observe mathematical cause-and-effect
Exponential Compounding Growth: Returns generate subsequent returns over time t, rapidly accelerating capital growth.
Variable Mechanics
Roles, constraints & impacts
Amount
Formula Parameter
GST / VAT Rate
Formula Parameter
Mode (1 = add, 2 = remove)
Formula Parameter
At a Glance
Gotchas, units & real-world use
Formula Nature & Mechanics
Exponential Compounding Growth: Returns generate subsequent returns over time t, rapidly accelerating capital growth.
Common Mistakes & Traps
- Entering annual percentage rate (e.g. 7%) as 7 instead of converting to decimal 0.07.
- Neglecting the compounding frequency (n): monthly compounding produces higher yield than annual.
- Ignoring inflation drag when evaluating long-term nominal returns.
Dimensional Analysis & Units
Currency × (1 + rate)^time = Future Currency ($)
Real-World & Industry Application
Retirement 401(k) / Roth IRA compounding, mortgage amortization schedules, bond yield analysis, and inflation depreciation modeling.
Worked Example: GST / VAT
Given:
- amount = 1000
- rate = 18
- mode = 1
- GST = $1,000 × 18% = $180
- Split for intra-state supply: CGST 9% = $90, SGST 9% = $90
- Total including GST = $1,000 + $180 = $1,180
Answer: 1180
Frequently Asked Questions
What is the GST / VAT formula?
Add: Total = Amount × (1 + rate) · Remove: Base = Amount ÷ (1 + rate). Add GST/VAT to a price or remove it from a tax-inclusive price. Mode: 1 = add tax, 2 = remove tax.
How do I calculate GST / VAT?
Enter Amount (amount), GST / VAT Rate (rate), Mode (1 = add, 2 = remove) (mode) into the calculator. It applies Add: Total = Amount × (1 + rate) · Remove: Base = Amount ÷ (1 + rate) and shows every step of the working.
