Blog
Practical guides on everyday maths, personal finance, and how to get the most from our free calculators. All articles are free to read, with no login required.
What You'll Find Here
Every article on this blog is written to be genuinely useful — not just to explain a formula, but to show why it matters in real life. Whether you're trying to understand how compound interest works on your savings account, figure out the true cost of a credit card balance, or simply get faster at mental arithmetic, these guides are designed to give you practical knowledge you can use the same day you read them.
The blog covers three main areas: mathematics (from order of operations to the quadratic formula), personal finance (interest, loans, tax, budgeting), and practical calculator tutorials (how to use our tools to solve real problems faster). Articles are written by Alex van den Berg, a mathematics educator with over eight years of experience teaching applied maths and personal finance.
New articles are added regularly. If you have a topic you'd like covered — a formula you've never been able to remember, a financial concept that's always confused you, or a question about how one of our calculators works — get in touch and we'll do our best to write a guide for it.
How to Calculate VAT: A Complete Guide
Learn how to add VAT, remove VAT, and work with different VAT rates. Includes practical examples for businesses and shoppers.
Understanding Exchange Rates & Currency Conversion
Discover how exchange rates are set, what drives currency values, and how to convert money at the best rate.
Percentage Calculations Explained: Basics to Advanced
Master percentages: discounts, tax, tips, percentage change, and real-world applications in daily life.
Scientific Calculator Guide: Mastering Advanced Functions
How to use trigonometric functions, logarithms, factorials, and scientific notation with confidence.
Budgeting Made Easy: Using Calculators for Personal Finance
Practical tips for managing your budget, tracking expenses, setting savings goals, and making smarter financial decisions.
Calculator Tips & Shortcuts Everyone Should Know
Time-saving keyboard shortcuts, memory tricks, and chained expressions that make everyday calculations faster.
How to Calculate Compound Interest: The Complete Guide
Understand how compound interest works, the formula to use, and how it grows savings exponentially over time.
Simple vs Compound Interest: Key Differences Explained
The crucial difference between simple and compound interest and how each type affects your savings and loan repayments.
Order of Operations: PEMDAS, BODMAS & BEDMAS Explained
Master the rules that govern mathematical calculations. Essential reading before using any calculator.
Essential Maths Formulas: Complete Quick-Reference Guide
A practical reference of everyday maths formulas — geometry, finance, statistics — with examples you can try in the calculator.
How to Calculate Discounts and Sale Prices
Work out exact savings, final prices, and stacked discounts when shopping. Includes quick mental-maths methods.
Mental Maths Tricks: Calculate Faster Without a Calculator
Powerful techniques for multiplication, percentages, and estimation that work in your head — great for when no device is handy.
Understanding Profit Margins: How to Calculate & Improve Them
Calculate gross and net profit margins, understand markup vs margin, and find levers to improve business profitability.
Understanding Loan Payments and Amortisation
How monthly loan payments are calculated, what amortisation means, and how to compare mortgage and loan offers.
How to Calculate Area and Perimeter: Complete Guide
Formulas for every common shape — squares, circles, triangles — with practical examples for home improvement projects.
Unit Conversions Guide: Length, Weight, Volume & Temperature
Quick-reference formulas and tables for converting between metric and imperial units, with worked examples.
How to Calculate Tips: A Complete Guide to Tipping
Calculate tips quickly, understand tipping customs by country, and learn the best mental-maths shortcuts for restaurants.
The True Cost of Credit Card Debt (Interactive Calculator)
See exactly how long minimum payments take and how much interest you pay. Includes an interactive payoff calculator — the numbers will shock you.
What Inflation Really Does to Your Money (+ Interactive Tool)
Discover how inflation silently erodes your purchasing power — with an interactive calculator showing real vs nominal value over time.
Salary Negotiation Maths: Compare Job Offers Properly
The headline salary is misleading. Use our interactive job offer calculator to factor in pension, holiday, commute costs, bonus, and tax brackets.
Free Interactive Tools
Maths Formula Library
50+ formulas covering algebra, geometry, finance, statistics and trigonometry — searchable and with worked examples.
Open Library →Mental Maths Practice
Timed drills to sharpen your mental arithmetic. Choose difficulty, operation type, and track your score. Free to play.
Start Practice →Ready to Calculate?
Put what you've learned into practice with our free online calculators — no login required.