Free calculators that show their working
These calculators answer everyday number questions quickly and show the formula behind every result, so you can trust the answer and learn the method. Like every tool on AllSEOToolkit, they run entirely in your browser with no sign-up and no limits.
The Percentage Calculator covers the questions people ask most: what X% of a number is, what percent one number is of another, percentage increase and decrease, adding or subtracting a percentage, percentage difference and discounts.
More calculators on AllSEOToolkit
For writing, the Reading Time Calculator estimates how long an article takes to read, and the Speaking Time Calculator times a speech or video script. The Keyword Density Checker works out how often each word and phrase appears in a page as a percentage of all its words.