Free · No Ads · No Limits

The calculator
that thinks
like you do.

Calc Pro is a premium iPad-style calculator with a full scientific panel, persistent history, dark & light mode, and keyboard shortcuts — all in your browser, instantly.

Open Calculator See Features
26/26
Math tests passing
0.1+0.2
= 0.3 ✓ Fixed
30+
Scientific functions
🌙
Dark Mode
Auto-saved preference
⌨️
Keyboard Ready
Full shortcut support
📐
Scientific Mode
sin, cos, tan, log…
sin(30) + √144 =
12.5
AC
+/−
%
÷
7
8
9
×
4
5
6
−
1
2
3
+
0
.
=
No eval() — safe math engine
Floating point precision fixed
Works offline (PWA)
Zero dependencies to install
Fully accessible (WCAG)
Everything you need

Built for precision.
Designed for delight.

Every feature is crafted to make calculation feel effortless — from basic arithmetic to complex scientific expressions.

Precision Math Engine
Powered by math.js — never uses eval(). Handles BODMAS correctly, fixes floating point errors, and supports complex expressions with nested parentheses.
// The infamous floating point bug — fixed
evaluate("0.1 + 0.2") → 0.3 ✓
evaluate("2 + 3 × 4") → 14 ✓
evaluate("sin(30)") → 0.5 ✓
evaluate("1/0") → "Cannot ÷ by 0" ✓
Calculation History
Every calculation is saved. Scroll back, tap to reuse any result. Persisted across sessions via localStorage.
sin(45) + cos(45) 1.414
factorial(7) 5040
√(144) × π 37.699
Scientific Panel
30+ functions including trig, inverse trig, logarithms, powers, roots, factorial, constants π and e, and DEG/RAD toggle.
sincostan sin⁻¹cos⁻¹tan⁻¹ logln√ ∛x²xʸ πen! |x|()
Dark & Light Mode
Seamlessly switch between a deep charcoal dark theme and a crisp white light theme. Your preference is remembered.

Toggle with the ☀️ button — saved to localStorage

Full Keyboard Support
Every key mapped. Type expressions at full speed without touching the mouse.
0–9+ - × /Enter BackspaceEscape( ) sct lrh
Installable PWA
Install Calc Pro on any device — desktop, tablet, or phone. Works fully offline once installed. No app store required. No updates to manage.
Works Offline
Installable
Instant Load
Bulletproof Error Handling
Division by zero, syntax errors, overflow, and floating point issues are all caught gracefully — with clear messages, never crashes.
5 ÷ 0 Cannot ÷ by 0
2 ++ 3 Syntax Error
0.1 + 0.2 0.3 ✓
Simple by design

Up and running
in seconds.

No installation, no account, no friction. Just open and calculate.

1

Open in browser

Visit the link on any device — desktop, tablet, or phone. No download required. Loads in under a second.

2

Start calculating

Click buttons or use your keyboard. Switch to scientific mode for advanced functions. Toggle dark/light mode to your preference.

3

Review & reuse

Open the history panel to see all past calculations. Tap any result to load it back. Copy results with one click.

Scientific Mode

From basic to advanced — one tap away.

Hit the Scientific button to reveal a full panel of 18 advanced functions. Inverse trig, logarithms, powers, roots, constants — all organized and accessible.

  • Trigonometric: sin, cos, tan and their inverses
  • Logarithmic: log₁₀ and natural log (ln)
  • Powers: x², x³, xʸ and roots √, ∛
  • Constants π and e with implicit multiplication
  • DEG/RAD toggle for angle mode
Inv
sin
cos
tan
log
ln
π
e
x²
x³
√
∛
(
)
n!
xʸ
|x|
DEG
History Panel

Never lose a calculation again.

Every expression and result is automatically saved with a timestamp. Open the history panel to scroll through your work and tap any entry to instantly reload it.

  • Stores up to 50 recent calculations
  • Persisted in localStorage across sessions
  • Click any entry to reuse the result
  • Timestamps for every calculation
  • One-click clear all
sin(45) + cos(45)
1.414
2:34 PM
factorial(7)
5040
2:31 PM
√144 × π
37.699
2:28 PM
What users say

Loved by students,
engineers & developers.

"Finally a web calculator that doesn't give me 0.30000000000004 for 0.1+0.2. The precision is spot on and the scientific panel is everything I need for my engineering coursework."

A
Aisha K.
Mechanical Engineering Student

"The keyboard shortcuts are a game changer. I can type full expressions without touching the mouse. The history panel means I never have to re-enter the same formula twice."

M
Marcus T.
Full-Stack Developer

"The dark mode is gorgeous and the animations feel premium. It genuinely feels like a native iPad app. I installed it as a PWA and use it every day for quick calculations."

S
Sofia R.
UX Designer
Power User

Master the keyboard.
Calculate at the speed of thought.

Every button has a keyboard equivalent. Once you learn the shortcuts, you'll never reach for the mouse again.

Calculate result
Enter=
Delete last character
Backspace
Clear all
Escape
Sine / Cosine / Tangent
sct
Log / Natural log
ln
Square root / Pi
rp
Toggle history panel
h
Free forever

Ready to calculate
smarter?

Open Calc Pro in your browser right now. No sign-up, no download, no ads. Just a beautiful, powerful calculator.

Open Calc Pro — It's Free

Works on Chrome, Safari, Firefox, Edge · Desktop & Mobile · Installable PWA