How to Use a Scientific Calculator Online
A scientific calculator handles math that a basic calculator can't — trigonometry, logarithms, square roots, exponents, factorials, and more. Whether you're a student, engineer, or just someone who needs to crunch specific numbers, our free Scientific Calculator works on any device without any download or app.
This guide explains every major function so you can use the calculator with confidence — even if it's been years since your last math class.
What Is a Scientific Calculator?
A scientific calculator goes beyond addition, subtraction, multiplication, and division. It handles:
- Trigonometric functions: sine, cosine, tangent (and their inverses)
- Logarithms: log (base 10) and ln (natural log)
- Exponents and powers: squaring, cubing, any power
- Square roots and nth roots
- Factorials
- Constants: π (pi), e (Euler's number)
- Memory functions: store and recall values
Physical scientific calculators like the Casio fx-991EX or Texas Instruments TI-36X cost $15–$30. Our online version is free and always accessible on your phone or computer.
Scientific Calculator Quick Reference
| Button | What It Does | Example | |---|---|---| | sin / cos / tan | Trigonometric functions | sin(30°) = 0.5 | | sin⁻¹ / cos⁻¹ / tan⁻¹ | Inverse trig (find the angle) | sin⁻¹(0.5) = 30° | | log | Logarithm base 10 | log(100) = 2 | | ln | Natural logarithm (base e) | ln(e) = 1 | | x² | Square a number | 5² = 25 | | xⁿ | Raise to any power | 2^10 = 1024 | | √ | Square root | √144 = 12 | | ⁿ√ | Nth root | ³√27 = 3 | | n! | Factorial | 5! = 120 | | π | Pi constant | π ≈ 3.14159... | | e | Euler's number | e ≈ 2.71828... | | EXP / ×10ⁿ | Scientific notation | 3 EXP 6 = 3,000,000 |
How to Use Trigonometric Functions
Trigonometry is used in construction, navigation, physics, engineering, and many other fields. Here's how to use sin, cos, and tan:
Degrees vs. Radians
Before calculating trig functions, check whether the calculator is in Degree (DEG) or Radian (RAD) mode:
- Degrees: Most everyday uses — angles you see on blueprints, maps, clocks
- Radians: Used in higher math and physics — π radians = 180°
To switch modes on our Scientific Calculator, look for the DEG/RAD toggle at the top.
Common Trigonometry Values
| Angle (Degrees) | 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 |
Example: Find the height of a building
If a building casts a shadow of 50 meters and the sun is at a 35° angle: Height = 50 × tan(35°) = 50 × 0.7002 = 35.01 meters
On the calculator: type 50 × tan(35) and press =.
How to Use Logarithms
Logarithms tell you what power you need to raise a base to in order to get a number.
- log(1000) = 3 because 10³ = 1000
- ln(e²) = 2 because e² = e²
When to Use log vs. ln
- log (base 10): Used in science (pH levels, decibels, earthquake magnitude), business, and statistics
- ln (natural log): Used in calculus, compound interest, population growth, and physics
Example — Compound interest using ln: How long does it take to double money at 7% interest (compounded continuously)? Time = ln(2) ÷ 0.07 = 0.693 ÷ 0.07 = 9.9 years
How to Use Exponents and Powers
- x² squares the number on screen:
5 x²= 25
- xⁿ raises to any power:
2 xⁿ 10 =gives 1,024
- 10ˣ is the inverse of log:
10ˣ 3 =gives 1,000
- eˣ is the inverse of ln:
eˣ 2 =gives 7.389
How to Use Memory Functions
Memory functions let you store an intermediate result and recall it later — useful for multi-step problems:
- M+ — Add the current number to memory
- M- — Subtract the current number from memory
- MR / RCL — Recall the stored value
- MC / MClr — Clear the memory
Example: Calculate (15 + 27) × (18 - 6)
1. Calculate 15 + 27 = 42, press M+
2. Calculate 18 - 6 = 12
3. Press × then MR (recalls 42)
4. Press = → result is 504
Scientific Notation on a Calculator
Scientific notation is used for very large or very small numbers:
3.6 × 10⁶= 3,600,000
1.5 × 10⁻⁴= 0.00015
On the calculator, use the EXP or ×10ⁿ button:
3.6 EXP 6 = 3,600,000
This is common in chemistry (Avogadro's number: 6.022 × 10²³), physics, and astronomy.
Who Uses a Scientific Calculator?
- Students: Algebra, geometry, trigonometry, pre-calculus, physics, chemistry
- Engineers: Structural calculations, electrical formulas, force and stress analysis
- Finance professionals: Compound interest, loan amortization, statistical analysis
- Scientists: Lab calculations, unit conversion, data analysis
- Contractors: Angle calculations, material estimates, load calculations
Frequently Asked Questions
What's the difference between a scientific calculator and a regular calculator? A basic calculator handles addition, subtraction, multiplication, and division. A scientific calculator adds trigonometric functions (sin/cos/tan), logarithms (log/ln), exponents, roots, factorials, and constants like π and e. Our free Scientific Calculator includes all of these functions and works on any device.
Should I use DEG or RAD mode? Use Degree (DEG) mode for everyday angles — navigation, construction, geometry class. Use Radian (RAD) mode for calculus, physics, and any math that involves π in the angle measurement. When in doubt, check what unit your problem uses and match it in the calculator.
How do I calculate sin⁻¹ (inverse sine / arcsine)? Press the 2nd or Shift button on the calculator, then press sin. This activates the inverse sine function (sin⁻¹). Enter the value and press equals. For example, sin⁻¹(0.5) = 30°. This tells you the angle whose sine is 0.5.
Can I use this scientific calculator on my phone? Yes. Our Scientific Calculator is fully responsive and works on any smartphone browser. No app download required — just open it in Chrome, Safari, or any mobile browser and it's ready to use.