Scientific Calculator

Trig, logs, powers, factorials & constants — a safe offline expression engine.

Trig, logs, powers, factorials & constants — a safe offline expression engine. Free and 100% private — runs entirely in your browser, nothing is ever uploaded.

About Scientific Calculator

The Scientific Calculator on ToolsDeck is a free, offline expression calculator that evaluates whole math expressions with correct order of operations, parentheses, powers, factorials, and trig functions in degrees or radians. Use it for homework, engineering checks, or any quick calculation where you want to type an expression like sin(45) + 2^10 / (3!) and see the answer update live as you type. It runs 100% in your browser using a safe, non-eval engine, so nothing you enter is ever uploaded to a server.

How to use Scientific Calculator

  1. Type a full expression into the input box, for example 2^10 + sqrt(144), or use the on-screen button pad to insert digits, operators, and functions.
  2. Watch the large result line update live as you type; there is no need to press equals to preview the answer.
  3. Toggle RAD or DEG at the top before using sin, cos, or tan so your angles are interpreted in the right unit.
  4. Press Enter or the = button to commit a result to History; the answer is carried forward so you can keep calculating from it.
  5. Click any item in History to recall that result back into the input, or use Copy result to put the number on your clipboard.
  6. Insert constants like pi and e, take factorials with !, and group with parentheses to control order of operations.

Frequently asked questions

Does the % button calculate percentages?
No. In this calculator the % operator is modulo (the remainder of a division), so 10 % 3 returns 1. If you need percentage math like discounts, tips, or percent-of-a-number, use the dedicated Percentage Calculator instead.
How do I switch between degrees and radians for trig?
Use the RAD / DEG toggle at the top of the tool. It only affects trig functions: in DEG mode, sin(30) returns 0.5; in RAD mode, sin(30) is interpreted as 30 radians. Inverse trig (asin, acos, atan) returns results in the matching unit.
What functions and constants are supported?
Functions include sin, cos, tan, asin, acos, atan, sinh, cosh, tanh, ln, log (base 10), log2, sqrt, cbrt, exp, abs, floor, ceil, round, sign, and fact. Constants include pi, e, tau, and phi. You can also write powers with ^, factorials with !, and even hex (0x), binary (0b), and scientific (1e3) numbers.
Is anything I type sent to a server?
No. The calculator runs entirely in your browser with a small, sandboxed evaluator that does not use JavaScript eval. Your expressions and history never leave your device, so it works offline and keeps your data private.
Why do I get an error or no result sometimes?
The engine validates input and only allows known numbers, operators, constants, and functions. Common causes are mismatched parentheses, a missing operand, an unknown name, or a factorial of a non-integer. Fix the highlighted expression and the live result reappears.