How to use the scientific calculator
Type an expression the way you would write it on paper, or tap the keys. The answer appears in grey as you type, and pressing = or Enter fixes it, stores it as Ans and adds it to the history. Press Esc to clear and Backspace to delete.
You can type function names straight from your keyboard: sin(30), sqrt(2), log(1000), ln(e), 5!, 2^10, 3E8. Multiplication signs can be left out where the meaning is clear, so 2π, 3(4+1) and 2sin(30) all work.
Order of operations
The calculator follows the standard order that maths teachers call BODMAS or PEMDAS.
| Priority | Operation | Example | Result |
|---|---|---|---|
| 1 | Brackets | (2 + 3) × 4 | 20 |
| 2 | Factorial, percent, square | 3 + 2² | 7 |
| 3 | Powers (right to left) | 2^3^2 | 512 |
| 4 | Minus sign in front | −2^2 | −4 |
| 5 | Multiply and divide (left to right) | 8 ÷ 2 × 4 | 16 |
| 6 | Add and subtract (left to right) | 10 − 4 − 3 | 3 |
Two rules surprise people. First, powers stack from the right: 2^3^2 means 2^(3^2) = 2^9 = 512, not 8^2 = 64. Second, a minus sign in front of a power applies after the power, so −2^2 = −(2 × 2) = −4. Type (−2)^2 if you want 4. Phone calculators sometimes disagree on these, which is why this one shows its answer as you type.
Degrees or radians?
Trigonometry functions need to know how angles are measured. A full turn is 360 degrees or 2π radians.
In DEG mode, sin(30) = 0.5, cos(60) = 0.5 and tan(45) = 1. In RAD mode the same keys work in radians, so sin(π/6) = 0.5 and sin(30) gives −0.988, the sine of 30 radians. If a trig answer looks strange, check the mode first. School geometry questions are usually in degrees; calculus and physics formulas usually use radians.
The inverse functions (sin⁻¹, cos⁻¹, tan⁻¹) go the other way and give an angle in the current mode: sin⁻¹(0.5) = 30 in DEG mode or 0.5236 in RAD mode. sin⁻¹ and cos⁻¹ only accept values from −1 to 1, because a sine or cosine can never be outside that range.
At angles like 30°, 45°, 90° and 180° the calculator returns the exact value (for example sin(180) = 0 and cos(90) = 0), rather than a tiny leftover such as 0.0000000000000001 from floating-point rounding. tan(90°) is undefined, so it shows an error instead of a huge meaningless number.
Logs, powers and roots
- log is the common logarithm, base 10: log(1000) = 3 because 10³ = 1000.
- ln is the natural logarithm, base e ≈ 2.71828: ln(e) = 1. Use eˣ to undo it.
- xʸ raises to any power: 1.05^10 ≈ 1.6289, the growth of money at 5% a year for 10 years.
- √ and ∛ take square and cube roots. You can also write a root as a power: 8^(1/3) = 2. Cube roots of negative numbers are real, so ∛(−27) = −3.
- n! multiplies all whole numbers up to n: 5! = 5 × 4 × 3 × 2 × 1 = 120. It only accepts whole numbers from 0 to 170; 171! is larger than the biggest number the calculator can hold.
Worked example (compound growth): how long does money take to double at 7% a year? Solve 1.07^t = 2, so t = ln(2) ÷ ln(1.07). Type ln(2)/ln(1.07) to get 10.24 years. For full savings plans, the compound interest calculator does this with deposits and inflation.
Worked example (right triangle): a ladder 5 m long leans at 70° to the ground. How high does it reach? Height = 5 × sin(70°). In DEG mode, 5sin(70) gives 4.698 m.
Percent, EXP and memory
The % key divides by 100, so 50% = 0.5 and 200 × 10% = 20. After a plus or minus it works like a shop calculator: 100 + 10% = 110 and 80 − 25% = 60. For every kind of percentage question, the percentage calculator explains each formula.
EXP enters a power of ten, written with a capital E: 3E8 means 3 × 10⁸, the speed of light in metres per second. Very large and very small answers are shown the same way, for example 6.02214076E23, so you can copy them back in.
The memory keys hold one number while you work. M+ adds the current answer to memory, M− subtracts it, MR puts the stored number into your expression and MC clears it. Ans always holds the last answer you got with =.
Accuracy
The calculator uses standard 64-bit floating-point numbers, the same as spreadsheets and programming languages. That gives about 15 to 16 significant digits, and results are shown rounded to 12 so that 0.1 + 0.2 reads 0.3 instead of 0.30000000000000004. For exact answers with fractions, such as 1/3 + 1/6 = 1/2, use the fraction calculator, which never rounds.
Your expressions are read by the calculator’s own parser, never run as code, and nothing you type leaves your browser.