Summary: how to use a scientific calculator online for free
A scientific calculator is a calculator that goes beyond arithmetic to handle brackets, trigonometry, logarithms, powers, roots and factorials. To use this one, build your expression with the keys or keyboard, glance at the live = preview above the display, and press =. Angles are in degrees by default; switch to RAD for radians.
Operations follow the usual order: brackets, powers and roots, multiplication and division, then addition and subtraction. Results show up to 15 significant digits, so 0.1 + 0.2 appears as 0.3. Everything is calculated in your browser, and nothing you enter is uploaded.
Table of use: example calculations
| Calculation | Result | What it shows |
|---|---|---|
| 2 + 3 × 4 | 14 | Multiplication before addition |
| sin(30) + √16 (DEG) | 4.5 | Functions combined in one expression |
| −2² and (−2)² | −4 and 4 | The sign is applied after the power unless bracketed |
| 2^3^2 | 512 | Powers are worked out right to left |
| 200 + 10% | 220 | % after + or − is a percentage of the running total before it |
| log(1000) and ln(e) | 3 and 1 | Base 10 and natural logarithms |
| sin⁻¹(0.5) (INV, DEG) | 30 | Inverse trig returns an angle in the chosen unit |
| sin(90) in RAD | 0.893996663600558 | Why the angle unit matters |
| 5! and 2π | 120 and 6.28318530717959 | Factorial, constants and implicit multiplication |
Degree and radian angles convert as radians = degrees × π ÷ 180, so 90° = π ÷ 2 ≈ 1.5708 radians. A logarithm answers “what power gives this number”, so log(1000) = 3 because 10³ = 1000.
Features
- Full expressions. Brackets nest, a missing closing bracket at the end is added for you, and a number next to a bracket, constant or function is multiplied, so 2π, 3(4 + 1) and 2sin(30) work.
- Trigonometry in DEG or RAD, with INV for sin⁻¹, cos⁻¹ and tan⁻¹. In degree mode, exact angles such as sin(180°) return exactly 0, and tan(90°) reports an error.
- Powers and roots: x², x³, xʸ, √, ∛, 1/x, 10ˣ and eˣ.
- Logarithms, factorial and constants: log, ln, n! for whole numbers from 0 to 170, π and e.
- Percent and sign keys: % follows the rule in the table, and ± flips the sign of the last number or bracketed group.
- Memory: MC, MR, M+, M− and MS, with the stored value shown beside the keypad.
- History: your last 20 results, each one clickable to reuse, with a Clear History button.
- Copy button and CE. Copy puts the current result on your clipboard, and CE removes just the last number.
- Clear errors: messages such as Cannot divide by zero or Math error name the problem instead of showing nonsense.
How to use the scientific calculator
- Pick DEG or RAD for trigonometry. Press INV if you want the inverse functions.
- Enter your expression with the on-screen keys or your keyboard. Function keys such as sin, log and √ open a bracket, so type the value next, then ).
- Check the live preview above the display. It shows the result of what you have typed so far.
- Press = on screen or on your keyboard; Enter does the same when no button has keyboard focus. Press an operator to carry on from the result, or a digit to start a new calculation.
- Use MS and MR for a value you need later, click a History entry to reuse an answer, and press C to clear everything.
Who can use it
Students working through algebra, trigonometry, logarithms and physics problems can use it for homework and revision, and engineers, makers and anyone who needs a quick root, power or factorial can use it without installing an app. It is a calculator, not a graphing tool: it does not plot functions or handle complex numbers, matrices or symbolic algebra.
For specific jobs, other calculators are quicker. The percentage calculator shows step-by-step working, the fraction calculator keeps fractions exact, and the unit converter, length converter and temperature converter change units. Geometry sums fit the area calculator and volume calculator, marks fit the grade calculator, and growth over time fits the compound interest calculator. For number bases, try the binary to hex converter, or browse the calculators hub.
Frequently asked questions (FAQs)
Does this scientific calculator follow the order of operations?
Yes. Brackets are worked out first, then powers and roots, then multiplication and division, then addition and subtraction, so 2 + 3 × 4 = 14. Powers are evaluated right to left (2^3^2 = 2^9 = 512), and a minus sign in front of a number is applied after the power, so −2² = −4 while (−2)² = 4.
Why does sin(90) not equal 1?
Check that DEG (degrees) is selected above the keypad. In RAD (radians) mode the calculator treats 90 as 90 radians, and sin(90 radians) is about 0.894, not 1. Switch to DEG for angles in degrees, or enter π ÷ 2 in RAD mode to get sin(π ÷ 2) = 1.
How does the % key work?
On its own, a percentage is divided by 100, so 50% = 0.5 and 2 × 50% = 1. After a plus or minus it is a percentage of everything before it (the running total), as on most handheld calculators: 200 + 10% = 220 and 200 − 10% = 180. For other percentage questions, use the dedicated percentage calculator.
What is the difference between log and ln?
log is the common logarithm, base 10, so log(1000) = 3 because 10³ = 1000. ln is the natural logarithm, base e ≈ 2.71828, so ln(e) = 1. Use log for orders of magnitude, such as pH or decibels, and ln for calculus, growth and decay. Neither accepts zero or a negative number.
How do I calculate a fourth root or other roots?
Use the power key (xʸ) with a fractional exponent in brackets. The fourth root of 16 is 16^(1/4) = 16^0.25 = 2, and the fifth root of 32 is 32^(1/5) = 2. The keypad has dedicated keys for the square root (√) and cube root (∛), so those need no exponent.
Can I type with my keyboard?
Yes. Type digits, the decimal point, + − * / ^ ( ) % and !, press = to calculate (Enter works too when no on-screen button has focus), Backspace to delete the last entry, Delete to clear the current number and Esc to clear everything. Functions such as sin, log and √ are on-screen keys, which open a bracket for you to type the value into.
Why do I see "Math error"?
The expression has no real-number answer, for example the square root of a negative number, the logarithm of zero or a negative number, sin⁻¹ of a value outside −1 to 1, tan(90°), or a factorial of a non-whole number. Dividing by zero shows "Cannot divide by zero", and factorials above 170 show an overflow message.
Is it safe to use for private calculations?
Yes. Every calculation runs in your browser, so nothing you enter is uploaded. History and memory exist only in the open page and are cleared when you close or reload it. You can verify this in the Network tab of your browser DevTools: pressing keys and = sends no requests.