The Calculator Den Blog

Practical money and everyday-maths articles that answer a real question, then hand you the calculator that does the work. No fluff, no filler.

The 30% rule is a decent starting point, but your real number depends on the rest of your budget. Here is how to find it.

The price on the windscreen is the smallest part of the story. Here is how to budget for the payment and everything that comes after it.

Rough milestones by age, and why the amount matters less than when you start.

Weight loss comes down to a calorie deficit. Here is how to find your number and a safe pace to aim for.

A clear plan beats willpower. Here are the two methods that work, and why even small extra payments go a long way.

Fuel is one of the easiest running costs to trim. Small habits add up to real money over a year.

Compound interest is the quiet engine behind almost every savings and investing story. Understand it once and the maths of money gets a lot clearer.

Nearly every percentage question is one of three sums. Learn the three and you can do most of them in your head.