OnSciCalc.
100% Free · No Installs · Double Precisionv2.0 Full-Screen Mode

在线科学计算器

功能全面的免费在线科学计算器，支持高精度运算、分数、三角函数、对数及历史记录。

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RAD科学模式
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计算器使用指南

运算优先级

OnSciCalc 严格按照数学代数优先级进行计算：

1. 括号 (Parentheses) ( ... )
2. 指数与幂 (Exponents) x^y
3. 三角与对数函数 sin, ln
4. 乘法与除法 (*, /) *, /
5. 加法与减法 (+, -) +, -

核心概念与参考

指数运算2^3

求数的幂次方。5^2 等于 25。

三角函数sin(30)

支持弧度与角度。RAD 模式下 cos(pi) = -1。

💡 开启 2nd 切换反三角函数 (sin⁻¹, cos⁻¹, tan⁻¹)、立方根 (∛)、eˣ 及 10ˣ。

隐式乘法(2+3)*4

自动将 3(4+2) 解析为 3 * (4+2) = 18。

常用对数与自然对数log(100)

log 为以10为底，ln 为以e为底。ln(e) = 1。

阶乘 (n!)4!

正整数连续相乘。4! = 24。

💡 键盘快捷键支持: 支持数字键、运算符、Enter 键求值、Esc 键清空。

Why Choose OnSciCalc as Your Online Scientific Calculator?

Engineered to replace costly hardware calculators with an ultra-fast, zero-distraction web interface accessible on any device.

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Double-Precision Accuracy

Computes complex formulas with 64-bit IEEE-754 precision up to 15 decimal places. Eliminates rounding errors in engineering, physics, and calculus problem sets.

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Full Trigonometry & Hyperbolics

Calculate sine, cosine, tangent, and their inverses (arcsin, arccos, arctan) with instant Degree and Radian switching. Perfect for triangle trigonometry and wave physics.

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Fractions & Mixed Numbers

Native fraction arithmetic allows adding, subtracting, multiplying, and dividing rational numbers while maintaining exact decimal conversion.

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Persistent History Tracking

Your previous calculations are automatically saved locally in browser storage. Click any past equation to immediately restore its result into your active workspace.

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Full Keyboard Shortcuts

Type naturally with your PC or Mac keyboard. Use Enter to evaluate, Esc to clear, ^ for exponents, and Shift shortcuts for secondary trigonometric functions.

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PWA & Offline Capability

Install as a lightweight desktop or mobile app. Built-in service workers allow the entire calculation engine to run offline when you have no internet access.

Supported Scientific Functions & Mathematical Operations

Arithmetic & Algebra Operations

  • Basic Operations: Addition (+), Subtraction (-), Multiplication (*), and Division (/).
  • Parentheses & Precedence: Strictly obeys algebraic order of operations (PEMDAS/BODMAS) with nested parentheses (...).
  • Absolute Value: abs(x) returns the non-negative magnitude of any value.
  • Percentages: % allows quick percentage calculations for statistics and finance.

Trigonometry & Angle Units

  • Primary Trig Ratios: sin(x), cos(x), and tan(x).
  • Inverse Trigonometry (Shift / 2nd): sin⁻¹(x) (arcsin), cos⁻¹(x) (arccos), and tan⁻¹(x) (arctan).
  • DEG & RAD Mode: Seamlessly toggle between degrees (360° per revolution) and radians (2π per circle) with one click.
  • Pi Constant: Built-in π ≈ 3.141592653589793.

Logarithms & Exponents

  • Common Logarithm: log(x) calculates base-10 logarithm (log(100) = 2).
  • Natural Logarithm: ln(x) calculates logarithm with base e (ln(e) = 1).
  • Arbitrary Powers: x^y evaluates any base raised to any exponent.
  • Exponential Constants: e^x and 10^x for exponential growth and decay models.

Radicals, Factorials & Combinatorics

  • Square Roots: √(x) returns the principal square root.
  • Cube Roots: ∛(x) via the 2nd key for cubic polynomial evaluations.
  • Factorial: n! calculates permutations and discrete mathematics sequences (5! = 120).
  • Square & Cube: Quick power buttons x² and x³.

OnSciCalc vs. Traditional Hardware Calculators

Comparing OnSciCalc with popular physical scientific calculators like the Casio fx-991EX, Texas Instruments TI-84 Plus, and basic desktop tools.

Feature / MetricOnSciCalc (Web)Casio fx-991EXTI-84 Plus CEDefault OS Calc
Price100% Free$25 – $35$120 – $150Free (Included)
Device AvailabilityAny Browser (Mac, PC, Phone, Tablet)Physical Hardware OnlyPhysical Hardware OnlyCurrent Desktop Only
Calculation HistoryPersistent Local History (Click to Recall)Lost on Power OffScrollable (Clears on Reset)Limited History
Physical Keyboard InputFull Support (Type with standard keys)Keypad Buttons OnlyKeypad Buttons OnlyBasic Keyboard
Display QualityCrisp High-DPI Retina DisplayLow-Resolution Dot Matrix320 × 240 Color LCDWindowed Display
Dark Mode & ThemesYes (OLED Black & Clean Light)No (Fixed LCD)NoOS Theme Dependent
URL Link SharingYes (1-Click Shareable Link)NoNoNo
AI Expression AssistanceYes (Live Suggestions)NoNoNo

Essential Math Formulas & Scientific Reference Sheet

Bookmark these fundamental scientific rules and identities for fast reference while working through math, physics, and engineering homework.

Trigonometric Identities

sin²(θ) + cos²(θ) = 1
tan(θ) = sin(θ) / cos(θ)
1 + tan²(θ) = sec²(θ)
sin(2θ) = 2 sin(θ) cos(θ)
cos(2θ) = cos²(θ) - sin²(θ)

Logarithm Laws

log(a · b) = log(a) + log(b)
log(a / b) = log(a) - log(b)
log(aⁿ) = n · log(a)
ln(e) = 1,  log₁₀(10) = 1
log_b(x) = ln(x) / ln(b)

Exponent & Power Rules

xᵃ · xᵇ = xᵃ⁺ᵇ
xᵃ / xᵇ = xᵃ⁻ᵇ
(xᵃ)ᵇ = xᵃᵇ
x⁻ᵃ = 1 / xᵃ  (x ≠ 0)
x⁰ = 1  (x ≠ 0)

Power-User Keyboard Shortcuts

Calculate twice as fast on desktop without moving your hands to the mouse:

0 – 9, .Digits
+, -, *, /Operators
Enter or =Calculate
Esc or CClear
BackspaceDelete
^Power
Shift + Ssin⁻¹
Shift + Ccos⁻¹

Frequently Asked Questions

Everything you need to know about using OnSciCalc's free online scientific calculator.

1.What is an online scientific calculator?▼
An online scientific calculator is a web-based calculation tool that runs in any modern browser to solve complex scientific, algebraic, and engineering equations. Unlike standard calculators, it supports trigonometry (sin, cos, tan), logarithms (log, ln), exponents, powers, roots, fractions, and factorials without requiring any hardware device or software installation.
2.Is this online scientific calculator free to use?▼
Yes, OnSciCalc is 100% free with no registration, no subscriptions, and no hidden usage limits. You can perform unlimited calculations on desktop, tablet, and mobile devices.
3.How do I calculate sin, cos, and tan with this online calculator?▼
To calculate trigonometric ratios, ensure your angle mode is correctly set to DEG (Degrees) or RAD (Radians). Type or click the trig function (e.g., sin, cos, tan), enter your angle, close the parenthesis, and press Enter. Click the '2nd' button to calculate inverse trigonometric functions: arcsin (sin⁻¹), arccos (cos⁻¹), and arctan (tan⁻¹).
4.How do I switch between degrees and radians?▼
Click the 'DEG' or 'RAD' toggle button in the calculator controls above the keypad. When set to DEG, 90° evaluates to sin(90) = 1. When set to RAD, π/2 evaluates to sin(π/2) = 1.
5.Can this online scientific calculator handle fractions?▼
Yes! You can compute fractions and mixed numbers using division syntax (e.g., (3/4) + (1/2)). OnSciCalc evaluates rational numbers with double-precision floating-point accuracy and avoids rounding errors common in standard calculators.
6.How does OnSciCalc compare to Casio fx-991EX and TI-84 Plus?▼
OnSciCalc offers the core mathematical features of popular physical calculators like the Casio fx-991EX ClassWiz and Texas Instruments TI-84 Plus, but with web-first conveniences: zero cost, zero battery dependency, large responsive display, click-to-recall calculation history, light/dark mode themes, and shareable URLs.
7.Does this online calculator save my calculation history?▼
Yes. OnSciCalc features a persistent calculation history panel. All your previous inputs and evaluated answers are saved locally in your browser's storage, allowing you to review your work or click any past expression to reload it instantly.
8.Can I use keyboard shortcuts on my computer?▼
Yes, OnSciCalc is fully optimized for desktop keyboard input. Use digit keys (0-9), operators (+, -, *, /), parentheses (), caret (^) for exponents, Enter for equals (=), Esc to clear, Backspace to delete, and Shift+S/C/T for inverse trig functions.
9.What is the difference between log and ln on a scientific calculator?▼
'log' represents the common logarithm with base 10 (log₁₀(100) = 2), whereas 'ln' represents the natural logarithm with base e (Euler's number ≈ 2.71828, where ln(e) = 1). Both functions are available on OnSciCalc.
10.Does this online scientific calculator work offline?▼
Yes. OnSciCalc is built as a Progressive Web App (PWA). Once loaded in your browser, the service worker caches the core calculation engine so you can continue using it even without an active internet connection.

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