Basic Maths Calculators

Quick, clear tools for everyday number problems, from working out discounts to comparing values and checking percentage changes.

Everyday maths made simpler

Basic maths comes up more often than we realise: comparing prices, checking a bill, understanding a discount, dividing costs or tracking progress towards a target. These calculators are designed to give a clear answer without needing to set out the formula yourself.

Using our calculators

Enter the values you know, choose the calculation that matches your question and the result will appear immediately. Check that you have entered the correct units and starting values, particularly when calculating a percentage increase or decrease.

Popular basic maths questions

  • What is 20% of a price?
  • What percentage of my budget have I spent?
  • What was the original price before a discount?
  • How much will a value be after a percentage increase?

Match the tool to the relationship

Use fractions or mixed numbers to retain fractional structure, percentages for comparisons with a chosen base, and ratios or proportions for scaling. Use the mean, median, mode and range tool for observations with equal weight, or the weighted-average tool when some observations have more influence. Identify the units and the question before entering numbers.

Frequently asked questions

What is the difference between a ratio and a percentage?

A ratio compares quantities. A percentage expresses a quantity relative to a chosen base of one hundred.

When should I use a mixed number?

It is useful when a quantity contains whole units and a fractional remainder, such as 2 1/4 metres.

Can I divide by zero?

No. Division by zero is undefined, including fractions with zero denominators.

Does a mean give every entry equal weight?

The ordinary arithmetic mean does. Unequal weights need a weighted calculation.