Guides
Short, practical guides that explain the formulas and concepts behind each calculator. Written for business owners, freelancers, and anyone who wants to understand the math.
VAT Explained: What It Is, How It Works, and Who Pays It
A clear, practical guide to Value Added Tax — how it differs from sales tax, how it is calculated, and what businesses need to know about UK, EU, and international VAT rates.
Margin vs Markup: The Difference That Costs Businesses Money
Margin and markup both describe profit, but they are calculated differently. Confusing them leads to pricing errors. This guide clears it up with formulas, a conversion table, and examples.
How to Calculate Discount: Percentages, Stacking, and Reverse Calculations
Learn how percentage discounts work, how to calculate the final price, and why stacking discounts does not mean adding them together. Includes formulas for finding original prices.
Break-even Formula Explained: Fixed Costs, Variable Costs, and the Math
Understand the break-even formula, what contribution margin means, and how to find the exact point where your business starts making profit. Includes worked examples for retail and SaaS.
VAT Rates by Country: Complete 2026 Guide to Global Tax Rates
A comprehensive reference of VAT, GST, and consumption tax rates for major economies worldwide. Includes UK, EU, Australia, Canada, India, and more.
VAT vs Sales Tax: What's the Difference and Why It Matters
VAT and sales tax both add cost to purchases, but they work differently. This guide explains the key differences, how each is calculated, and which countries use which system.
How to Price a Product: Formulas, Strategies, and Common Mistakes
Pricing determines profitability. This guide covers cost-plus pricing, margin-based pricing, competitive pricing, and the formulas behind each approach.
How to Calculate ROI: Formula, Examples, and Common Pitfalls
Return on investment measures the efficiency of an investment. Learn the ROI formula, see worked examples for marketing, real estate, and business investments, and understand ROI limitations.
Pricing Strategy Explained: From Cost-Plus to Value-Based Pricing
Choose the right pricing strategy for your business. This guide covers cost-plus, value-based, competitive, penetration, and premium pricing with real-world examples and the math behind each.
How Discounts Destroy Your Margin (And How Much More You Need to Sell)
A discount reduces your margin by more than you think. This guide shows the real math: how discounts shrink profit, the formula for required sales volume increase, and a reference table for every margin and discount combination.