Guides & Articles
Practical explanations to help you understand the numbers behind our calculators — from how mortgage repayments work to what your BMI actually means.
Calorie Calculator vs TDEE: Which One Should You Use?
The difference between a calorie calculator and a TDEE calculator, how BMR feeds into TDEE, and which tool gives you the right daily target for weight loss, gain, or maintenance.
Credit Card Payoff Calculator — How Long Until You Are Debt Free?
Find out how long it will take to pay off your credit card and how much interest you will pay. Includes worked examples and strategies to clear debt faster.
How Much Would a £25,000 Mortgage Cost?
Find out exactly what a £25,000 mortgage costs per month at different interest rates and terms. Includes worked examples and a breakdown of total interest paid.
How Much Would a £250,000 Mortgage Cost Per Month?
See exactly what a £250,000 mortgage costs monthly at current UK rates. Worked examples for different terms and interest rates, plus total interest paid.
How Much Would a Mortgage Cost for £180,000?
Find out what a £180,000 mortgage costs per month at different UK interest rates and terms. Includes worked examples and total interest comparisons.
BMI vs Body Fat: Which Matters More?
BMI and body fat percentage both measure different things. Learn when to use each, the limitations of BMI, and why body fat gives a more accurate picture of health.
Calorie Needs for a 62 kg, 178 cm Male: Maintenance Intake Explained
How many calories does a 62 kg male who is 178 cm tall need per day for maintenance? Worked example using the Mifflin-St Jeor equation with activity levels.
The Hamwi Formula: How to Calculate Your Ideal Body Weight
What the Hamwi formula is, how it works, and how to calculate your ideal body weight using it. Includes worked examples for men and women plus comparison with other methods.
Investment Rate of Return Calculator — How to Measure Your Returns
How to calculate your investment rate of return, what a good return looks like, and how to use an investment calculator to project future growth. Includes worked examples.
Ovulation Calculator vs Period Calculator: Planning Fertility
What ovulation and period calculators track, how they differ, and how to use both together for fertility planning or understanding your menstrual cycle.
Simple Interest vs Compound Interest: What's the Real Difference?
A clear comparison of simple and compound interest with worked examples showing how £10,000 grows differently under each method, and when each type applies.
Compound Interest Explained — How Your Money Grows Over Time
What compound interest is, how it is calculated, why it is so powerful for savings and investments, and how to use it against debt.
BMI: What It Is, How It's Calculated, and What Your Number Means
Body Mass Index explained — the formula, what healthy BMI ranges mean, the limitations of BMI as a health measure, and when to use other measurements instead.
How to Calculate Your Monthly Mortgage Repayments
Learn exactly how mortgage repayments are calculated, what affects your monthly payment, and how to use a mortgage calculator effectively. Includes UK examples.
How to Calculate Stamp Duty in the UK (2025 Guide)
A complete guide to UK stamp duty land tax (SDLT) — current rates, how it is calculated, first-time buyer relief, and examples to help you work it out.
Take-Home Pay in the UK Explained (2025/26 Tax Year)
Understand exactly how much of your salary you actually keep after income tax, National Insurance, and other deductions. Includes current 2025/26 rates and worked examples.
What Is VAT and How Is It Calculated in the UK?
A plain-English guide to UK VAT — the current rates, how to add and remove VAT, when businesses must register, and how to use a VAT calculator.