Calculator
A fast, safe on-screen calculator for everyday arithmetic.
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What is the Calculator?
The Zentry Tools calculator is a fast, on-screen calculator for everyday arithmetic. It supports addition, subtraction, multiplication, division and percentages, with full keyboard support and a running calculation history — all without ever leaving your browser.
How to use it
- Type numbers and operators using the on-screen buttons or your keyboard.
- Press = (or Enter) to calculate the result.
- Use C to clear the current expression, or Delete to remove the last character.
- Open History to see and reuse your recent calculations.
- Use the Copy button to copy a result to your clipboard.
Features
- Basic arithmetic: addition, subtraction, multiplication, division
- Percentage calculations
- Full decimal support
- Keyboard input support
- Clear and delete controls
- Persistent calculation history
- One-click copy of results
- Safe expression parsing — no unsafe eval()
Privacy
This calculator runs entirely in your browser. Your calculations are never sent to a server, and your history is stored only in your browser's local storage.
Frequently Asked Questions
Yes, you can use the % operator directly in an expression, e.g. 200 % 15 calculates a remainder-style percentage operation, or use the dedicated Percentage Calculator for common percentage scenarios.
Yes. History is saved only in your browser's local storage and is never transmitted anywhere.
Yes, all number keys, operators, Enter, Backspace and Escape are fully supported.