Calc Lab · 4 min read · Aug 2, 2026 · By Calc Lab Team
Business & Tax Math Explained: GST, Profit Margins & ROI
Master formulas behind GST inclusive vs exclusive taxes, gross profit margins, compound interest, and currency calculations.
Calculating tax amounts, profit margins, and interest payments accurately is essential for freelancers, small business owners, and financial planners.
Formula Breakdown
• **GST / VAT Exclusive**: `Tax Amount = Net Price × (Tax Rate / 100)`
• **GST / VAT Inclusive**: `Net Price = Gross Price / (1 + Tax Rate / 100)`
• **Gross Profit Margin**: `((Revenue - Cost) / Revenue) × 100`
Simulate tax calculations and profit margins instantly using PolyForge Calc Lab tools with zero data collection.