How to calculate percentages and sums in Chrome

TabCmdr's way

Do the math in the TabCmdr palette

TabCmdr is a keyboard launcher that lives in your browser. Its search box works as a calculator too, so you can do a sum without leaving the page or opening a new tab.

Before you start: add TabCmdr from the Chrome Web Store. It has a 7-day free trial and needs no account.

Step 1: Open the palette

Press ⌘+K on a Mac or Ctrl+K on Windows and Linux, on any page.

Step 2: Type the sum

The answer appears under Calculator at the top of the list while you type. Here, 20% of 4500 gives 900.

You can write sums the way you would on paper:

• Use +, -, * and /, and ^ for powers. Brackets work as you’d expect: (1299 * 3) - 150 gives 3747.
• Functions work too: sqrt(144) + 2^5 gives 44 and log(1000, 10) gives 3.
• Long answers are rounded to 12 significant digits: 1250 / 12 gives 104.166666667.

Step 3: Press Enter to copy

The answer row is already highlighted. Press Enter and TabCmdr copies the answer and closes the palette, so you can paste it straight into a form, a sheet or a message. A “Copied 900” message shows at the bottom of the page.

Work out percentages

Type percentages the way you’d say them out loud:

on is handy for tax, tips and markups, and the minus form works for discounts.

If no answer shows up

• There’s no operator. A number on its own, like 4500, isn’t a sum, so no answer appears. Add an operator or a function.
• The symbol isn’t one TabCmdr reads. ! for factorials doesn’t work, so 5! gives no answer.
• You’re after a conversion. Units, colors and number bases use to, like 100 km to miles. The calculator page lists those too.