Scientific Calculator
Free online scientific calculator with trigonometric, logarithmic, and exponential functions. Keyboard support, DEG/RAD modes, and expression history.
A full-featured scientific calculator that runs entirely in your browser — with trig functions, logs, powers, factorial, and keyboard shortcuts.
No signup. No ads. Your calculations stay private.
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Keyboard: numbers, operators, Enter = calculate, Esc = clear, s/c/t/l/q = sin/cos/tan/log/√
Degrees vs Radians
Degrees divide a full circle into 360 parts — intuitive for everyday use. Radians measure the angle based on the radius: a full circle is 2π radians (about 6.283). Most scientific formulas use radians, while engineering and everyday geometry use degrees.
To convert: degrees × π/180 = radians. Radians × 180/π = degrees. This calculator handles the conversion automatically — just toggle DEG/RAD mode. Getting this wrong is one of the most common mistakes in trig and physics.
Trigonometric Values Cheat Sheet
The exact values you'll need for homework, exams, and engineering:
| Angle | sin | cos | tan |
|---|---|---|---|
| 0° | 0 | 1 | 0 |
| 30° | 0.5 | 0.866 | 0.577 |
| 45° | 0.707 | 0.707 | 1 |
| 60° | 0.866 | 0.5 | 1.732 |
| 90° | 1 | 0 | undefined |
| 180° | 0 | -1 | 0 |
| 270° | -1 | 0 | undefined |
| 360° | 0 | 1 | 0 |
Memorisation trick: sin goes 0, ½, √2/2, √3/2, 1 for 0°, 30°, 45°, 60°, 90°. Cos is the same sequence in reverse. Tan is sin divided by cos at each angle.
Common Mathematical Constants
| Constant | Symbol | Value | Used For |
|---|---|---|---|
| Pi | π | 3.14159265... | Circles, trig, waves |
| Euler's number | e | 2.71828182... | Compound interest, growth/decay |
| Golden ratio | φ | 1.61803398... | Design, nature, architecture |
| Square root of 2 | √2 | 1.41421356... | Diagonal of a square, A-series paper |
| Natural log of 2 | ln(2) | 0.69314718... | Half-life, doubling time |
Key Functions Explained
Trigonometry (sin, cos, tan)
Relate angles to side ratios in right triangles. sin(30°) = 0.5 means the opposite side is half the hypotenuse. Used in physics, engineering, game development, and signal processing.
Logarithms (log, ln)
log is base-10 (powers of 10). ln is the natural log (base e). Logarithms turn multiplication into addition — essential for decibels, pH scales, and compound interest calculations.
Factorial (n!)
n × (n-1) × ... × 1. So 5! = 120. Factorials grow absurdly fast — 20! exceeds 2 quadrillion. Used in probability, permutations, and combinatorics.
Powers and Roots
x² squares a number. xⁿ raises to any power. √ finds the square root. Fundamental to area, Pythagorean theorem, exponential growth, and standard deviation.
Order of Operations Refresher
The calculator follows standard mathematical order (BIDMAS/PEMDAS):
So 2 + 3 × 4 = 14 (not 20). If you want addition first, use brackets: (2 + 3) × 4 = 20. When in doubt, add brackets to make your intent explicit.
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How to use this tool
Enter a mathematical expression using the buttons or your keyboard.
Use scientific functions like sin, cos, log, sqrt, and constants like π and e.
Press = or Enter to calculate. Use Ans to chain results into new calculations.
Common uses
- Trigonometric calculations for maths and physics
- Logarithmic and exponential computations
- Quick percentage and factorial calculations
- Engineering and scientific formula evaluation
- Student homework and exam preparation
- Converting between degrees and radians
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