Online scientific calculator guide

Choosing the best online calculator for your task

The best online calculator for you depends on the calculation. For addition or division, clear input and readable buttons matter. For scientific maths, check the functions, angle mode and answer format before you start.

• Fractions and roots: choose exact answers when you need a simplified fraction or surd.
• Angles: choose degrees or radians to match the question, and use inverse trig when finding an angle.
• Repeated calculations: use Ans to continue from the previous result.
• A comfortable display: choose clear colours on any device and a text size on a desktop.

GCSE Maths Calculator includes these controls in one free scientific calculator. For graphing or symbolic equation solving, use a tool designed for those tasks.

Basic arithmetic and percentages

The same calculator handles everyday number calculations. It follows the usual order of operations, so multiplication and division are carried out before addition and subtraction. Use brackets to group a calculation.

To calculate a percentage of an amount, multiply by the percentage and divide by 100. For example, 18% of 240 is 240 × 18 ÷ 100 = 43.2. A percentage key is not needed.

Exact answers and decimals

An exact answer keeps a value as a fraction, a surd or an expression involving π where supported, rather than rounding it to a decimal. Press S↔D to switch between the exact and decimal forms of the answer.

If a question asks for an exact answer, keep the fraction or surd. If it asks for decimal places or significant figures, round the decimal result to the requested accuracy.

Fractions and surds

The fraction button gives you a numerator box above a denominator box. Enter each part in its own box, using the arrow controls to move between them. The square-root button places everything in its box under the root bar.

A surd can sometimes be simplified: for example, √12 = 2√3. The calculator displays simplified exact forms where supported. Check the structure of the expression on screen before pressing equals.

Trigonometry: DEG, RAD and inverse functions

For an angle given in degrees, choose DEG. Choose RAD only when the angle is in radians. The wrong angle mode can produce a different answer even when the input is otherwise correct.

Use sin, cos or tan when you know the angle. To find an angle from a ratio, press and hold the corresponding button for sin⁻¹, cos⁻¹ or tan⁻¹. In DEG mode, sin⁻¹(0.5) = 30.

Continue a calculation with Ans

After an answer, press +, −, × or ÷ to continue from that answer automatically. For example, calculate 2 + 3 to get 5, then press + 2 and equals to get 7.

Starting with a number instead begins a fresh calculation. After the answer 5, typing 2 + 3 calculates 2 + 3, not 5 followed by 2 + 3. Press and hold equals to insert Ans explicitly.

Powers, roots and standard form

Use the square and cube buttons for x² and x³, or the power button for another exponent. The nth-root button lets you choose a root other than a square root.

Standard form expresses a number as a × 10ⁿ, with 1 ≤ a < 10 for a positive number. For example, 4.2 × 10³ = 4200. Use the power controls to enter the exponent, and check it stays in the raised box.

Use brackets to make the intended order of operations clear, especially for negative numbers, fractions and compound expressions.

Logarithms: log and ln

A logarithm tells you which power gives a number. Use the log button to enter a base and a value. For example, log₂(8) = 3 because 2³ = 8.

The ln button uses the natural logarithm, with base e. For real-number calculations, the value inside a logarithm must be positive; a log base must also be positive and different from 1.

Keyboard and display settings

• Type numbers and +, −, × or ÷ on the keyboard. Press Enter or = to calculate.
• Ctrl + = on Windows, or Cmd + = on Mac, inserts a plus sign.
• Backspace or DEL removes input. AC clears the current calculation.
• The arrow keys and on-screen arrow pad move the cursor through expression boxes.
• Start calculating straight away. On your first visit, colour choices appear after about three seconds, with text-size choices on desktops. Select Use these settings or Keep current settings. Your preferences are saved in this browser.
• Use the settings button beside the three-line menu to change your colour theme; desktops also have a text-size choice. The rounded dropdowns show your selection, and the whole settings panel previews the theme. Choose Custom to create your own colour palette.
• The window button opens the calculator in a movable laptop or desktop window with your current calculation. Supported browsers keep it above other windows; other browsers open a regular pop-out. Use the browser window controls to move or close it.
• The desktop window requests at least 480 × 640 pixels, within the available screen space. Its buttons keep their proportions when resized. The four-corner button expands the calculator to fullscreen when supported; an always-on-top window returns to the original page for fullscreen. The close button returns your calculation to the page.
• Phones and tablets keep the calculator on the main page, with Display settings and the site menu. Pop-out and fullscreen controls are hidden. If a desktop browser blocks pop-outs, a draggable in-page window provides Minimise and Restore calculator.

Is this calculator for exams?

This website is for revision, teaching and homework, not a replacement for an exam-permitted physical calculator. Practise with the model you will actually use, and follow your school and exam board's instructions.