How to use Calculator
- Type a sum with the keys or your keyboard, for example 1,250 × 3 + 480. The answer appears as you type.
- Press = or Enter to finish. The sum and its answer go into the history.
- Switch to Scientific for sin, cos, tan, logarithms, powers, roots and factorials, in degrees or radians.
- Copy the answer, or tap a line in the history to use it again.
Why use Calculator
Exact decimals
Money and measurements add up exactly: 0.1 + 0.2 is 0.3, not 0.30000000000000004.
Percent like a desk calculator
200 + 10% gives 220, and 2,500,000 × 12% gives 300,000.
History and memory
Your last 30 sums and the MC, MR, M+ and M− memory stay in this browser.
Keyboard ready
Type digits and + − × ÷ ^ ( ) on your keyboard. Enter gives the answer and Esc clears.
About this tool
This online calculator works like the simple one on your phone or desk, with a few extras. The answer updates as you type, open brackets close themselves, and the whole sum stays on screen so you can check it. Behind the keys it uses exact decimal arithmetic, so everyday sums with money, prices and measurements come out exact.
Scientific mode adds trigonometry in degrees or radians, natural and base-10 logarithms, powers and roots, factorials, the constants π and e, and Ans for the last answer. A small calculator is also one tap away on every ToolboxHere page: open it with the calculator button at the top, then put the answer straight into the box you were filling in.
Frequently asked questions
How does the percent key work?
Like a desk calculator: 200 + 10% adds 10% of 200 (220), 200 − 10% takes it off (180), and 200 × 10% gives 20.
Why does 0.1 + 0.2 give 0.3 here?
Many calculators on computers use binary numbers and show 0.30000000000000004. This one calculates in decimals, as you would on paper.
Can I use my keyboard?
Yes. Type numbers and + - * / ^ % ( ). Enter or = gives the answer, Backspace deletes and Esc clears.
Is my history saved?
Your last 30 calculations and the memory are kept in this browser only. Clear them with "Clear" in the history.
Is there a calculator on other pages?
Yes. The calculator button at the top of every page opens a small calculator, and "Use" types the answer into the box you were filling in.