What’s the difference between slots and named variables?

A/B/C are fixed slots. Choose New variable to create a custom name with its own value and note. Both kinds have directly editable values and can also be set from a calculation result.

Which numeric values can I enter or paste?

Use negatives, dot-decimal numbers or scientific notation, such as -12.5, .75 or 1e3. Commas must group thousands, such as 1,234.5. Press Enter or leave the field to validate and save. Invalid or out-of-range values show an error and preserve the previous saved value; fix the entry before using that variable in a calculation.

How do I insert a variable?

Use Insert A/B/C for slots or Insert… to pick any saved variable. The name is inserted into your expression.

Calculator with Variables

Save values, reuse them in calculations, and keep notes.

Expression

Result

History

Last 50

No calculations yet.

Calculator help

Press Enter or = to calculate. % divides a value by 100; for example, 200 * 20% = 40. Variable names are case-sensitive.

Edit a value and press Enter or leave the field to save. Use a dot for decimals, commas for thousands, or scientific notation such as -1.2e3.

Switch between Basic and Scientific modes; Deg and Rad choose the angle unit for trigonometry. Variables, notes and history are saved in this browser when storage is available.

Try a worked example with reusable variables

Hourly pay

Choose New variable, name it rate, and enter 25 as its Value.
Create another variable named hours with Value 7.5.
Calculate rate * hours to get 187.5.
For a six-hour day, reuse rate * 6 to get 150.

Add VAT to a subtotal

Create a variable named subtotal with Value 80.
Create a variable named vatRate with Value 20.
Calculate subtotal * (1 + vatRate%) to get 96.
Reuse the same rate with 125 * (1 + vatRate%) to get 150.

Edit values in Variables and press Enter or leave the field to save, or choose Use result to reuse a calculation. Use Insert… to pick a saved name, or type it exactly as saved.

Help & FAQ — Calculator with Variables

How to use

In Variables, edit A/B/C values and press Enter or leave the field to save, or choose New variable and enter a Name, Value and optional Note.
Build an expression with the keypad or your keyboard and press Enter or =.
Choose Use result in Variables, or Result → A/B/C on the keypad, to reuse the current result.
Insert A/B/C or Insert… to reuse saved variables and notes.

Use cases

Store recurring values like rent, tax rates, or constants for quick reuse.
Document calculations with variable notes and history for later reference.

Tips & FAQs

What’s the difference between slots and named variables?: A/B/C are fixed slots. Choose New variable to create a custom name with its own value and note. Both kinds have directly editable values and can also be set from a calculation result.
Which numeric values can I enter or paste?: Use negatives, dot-decimal numbers or scientific notation, such as -12.5, .75 or 1e3. Commas must group thousands, such as 1,234.5. Press Enter or leave the field to validate and save. Invalid or out-of-range values show an error and preserve the previous saved value; fix the entry before using that variable in a calculation.
How do I insert a variable?: Use Insert A/B/C for slots or Insert… to pick any saved variable. The name is inserted into your expression.

Formats & limits

Supports basic arithmetic, parentheses, and common scientific functions
Named variables must be unique identifiers (letters, numbers, underscores)
History stores the last 50 calculations

Privacy

All calculations, variables, notes, and history are saved locally in your browser.

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Updated

6 October 2026