Scientific Calculator
Online scientific calculator with trig, logs, roots and powers.
How to use
- Click the on-screen keys, or type directly: digits 0–9, decimal point, + − × ÷ (as * /), ^, parentheses, Enter to evaluate (=), Backspace to delete one character, Esc to clear.
- Trigonometry defaults to degrees (DEG): type 30 then press sin to get 0.5. Switch to radians with the "DEG / RAD" key, and open results are recalculated immediately.
- sin / cos / tan / ln / log / |x| / √ first act on the number on screen; when there is no number they insert a function prefix so you can build expressions such as sin(30+5) or √(9) with parentheses. x², 1/x and x! always act on the current number — enter a number first.
- Calculations follow mathematical precedence: powers first, then multiplication/division, then addition/subtraction; parentheses override the order. Pressing a second operator replaces the first one, and values next to π, e or ( get an implicit multiplication sign.
- Results keep up to about 10 significant digits and floating-point noise is trimmed automatically (0.1 + 0.2 shows 0.3). Invalid operations such as division by zero or the square root of a negative number show an error — press C or Esc to start over.
FAQ
Are trigonometric functions in degrees or radians?
The default is degrees (DEG), where sin(30) = 0.5 and cos(60) = 0.5. Pressing the DEG key on the keypad switches to radians — the key then reads RAD, and sin(30) is about −0.988 in radians. Open trig results are recalculated instantly when you switch modes.
How do I type with the keyboard?
Type digits, the decimal point and the keys + − * / ^ ( ). Press Enter or = to evaluate, Backspace to delete one character, and Esc to clear everything (same as the C key). If focus is inside an input or another control on the page, click the calculator area first.
Why doesn't 0.1 + 0.2 show 0.30000000000000004?
Computers store decimals as binary floating point, so 0.1 + 0.2 is internally a very long approximation. This calculator trims the result to about 10 significant digits and removes the noise tail on display, so you simply see 0.3.
What happens with division by zero or the square root of a negative number?
Dividing by zero, taking the square root of a negative number, the logarithm of a non-positive number, the reciprocal of 0, or a factorial outside 0–170 (non-negative integers only) shows an error and no result. Press C or Esc to reset. Results beyond about 1e308 are reported as too large.