Calculator
A simple and scientific calculator in one. Tap the keys or type on your keyboard and watch the answer appear as you go.
History
Your calculations will appear here. They are kept only on this device.
How to use the calculator
- Tap the keys or just type. The calculation sits on the top line and a live answer appears right under it.
- Press = or Enter. The answer becomes the main number and the full calculation moves up a line.
- To keep going with that answer, press an operator such as + or ×. To start fresh, simply type a new number.
- Switch to Scientific for trigonometry, powers, roots and logarithms. Pick DEG or RAD for angles.
- Tap any line in History to bring that calculation back and edit it.
How this calculator works
This is a full online calculator that works like the one on your phone, plus a scientific calculator one tap away. You can type a whole calculation such as 12.5 × (3 + 4.2) and see the answer before you even press equals. Nothing is sent anywhere: every calculation runs in your browser.
Order of operations
The calculator follows the standard order taught in school: brackets first, then powers and roots, then multiplication and division, and finally addition and subtraction, working from left to right.
2 + 3 × 4 = 14 (2 + 3) × 4 = 20
−2² = −4 (−2)² = 4
You can also skip the multiplication sign where it is obvious: 2π, 3(4 + 1) and (1 + 2)(3 + 4) all work. Unclosed brackets are closed for you when you press equals.
How the percent key works
The % key behaves like a shop calculator. After a plus or minus it takes a percentage of the number before it, so 200 + 10% gives 220 and 80 − 25% gives 60. Anywhere else it simply divides by 100, so 200 × 10% gives 20. For more percentage questions, such as percentage change, try the percentage calculator.
Degrees or radians?
Angles can be measured in degrees (a full turn is 360°) or radians (a full turn is 2π). In DEG mode, sin(30) is 0.5. In RAD mode, the same keys give −0.988, because 30 is read as 30 radians. If a trig answer looks wrong, check this switch first. Exact angles are handled cleanly, so sin(180) shows 0 and tan(90) is reported as undefined.
Scientific keys at a glance
- 2nd swaps several keys for their inverse: sin⁻¹, x³, the y-th root, the cube root, eˣ and 10ˣ.
- xʸ raises to any power. ʸ√x takes the y-th root, so
3 ʸ√ 27is 3. - EXP enters scientific notation:
6.02E23means 6.02 × 10²³. - Ans reuses the last answer, and mod gives the remainder of a division.
- n! is the factorial. Whole numbers up to 170 are exact; other numbers use the gamma function.
Accuracy
Results are rounded to 15 significant digits, which hides the tiny binary rounding errors computers make. That is why 0.1 + 0.2 shows 0.3 here, not 0.30000000000000004. Very large or very small answers switch to scientific notation, for example 1.5E20.
Frequently asked questions
How do I switch to the scientific calculator?
Tap Scientific above the display. The extra keys for trigonometry, powers, roots and logarithms appear, and the calculator remembers your choice next time.
Does the calculator follow the order of operations?
Yes. Brackets come first, then powers, then multiplication and division, then addition and subtraction. For example, 2 + 3 × 4 gives 14, not 20.
How does the percent key work?
After plus or minus it takes a percentage of the number before it: 200 + 10% = 220. Otherwise it divides by 100: 200 × 10% = 20.
Why does sin(30) not give 0.5?
The calculator is probably set to radians. Switch the angle unit above the display to DEG and sin(30) will give 0.5.
Is my calculation history saved?
Only in your own browser, so it is there when you come back. Nothing is uploaded. Press Clear in the history panel to delete it.