About Calculator
A scientific calculator that handles parentheses, percentages, exponents, and the usual trig and logarithm functions. Every calculation is saved to a local history you can re-use with one click. The expression engine is hand-built (no `eval`), so what you type is what gets computed — safely.
- No uploads
- Browser-only
- Works offline
- 100% free
How it works
- 1
Type an expression
Use the on-screen keypad or your keyboard. Parentheses, π, and `e` are supported.
- 2
See the live preview
The result updates as you type. Press Enter or = to commit it to history.
- 3
Re-use past results
Click any history row to reload the expression. History persists in your browser.
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Frequently asked questions
Is it safe to type into?
Yes. The calculator uses a custom recursive-descent parser — `eval()` and `Function()` are never called. Hostile input can't escape the math sandbox.
Which functions are supported?
sin, cos, tan, asin, acos, atan, log (base 10), ln, exp, sqrt, abs, floor, ceil, round. Constants π and e are recognised by name.
Are angles in degrees or radians?
Radians, like JavaScript's `Math.*`. Convert with degrees × π/180 if needed.
Does it work offline?
Yes. SnapToolz is a Progressive Web App. After your first visit, the app is cached on your device and every tool keeps working without an internet connection.