Multi-Panel Calculator Layout
Open up to 8 independent calculators at once. Each panel runs its own mode, history, and state. Compare prices, run scenarios, or solve homework problems — all in parallel without switching screens.
Available free on iPhone & iPad · No ads · No account needed
Multiple Calculators.
One Screen.
CalcBoard is the multi-panel calculator app for iPhone and iPad. Run up to 8 independent calculators side by side, share values between panels, and switch between basic, scientific, programmer, and unit converter modes — all on one screen. No mainstream calculator app does this.
Panel 1
Basic
24.99 + 18.50
43.49
7
8
9
÷
4
5
6
×
1
2
3
−
0
.
←
=
Panel 2
Scientific
sin(45) × 2
1.4142135
sin
cos
tan
π
ln
log
√
^
7
8
9
÷
4
5
6
=
Panel 3
Programmer
BIN 1111 1111 · HEX FF
255
BIN
OCT
DEC
HEX
AND
OR
XOR
<<
A
B
C
>>
D
E
F
=
Value Tray:
43.49 ← Panel 1
1.4142 ← Panel 2
255 ← Panel 3
0
Ads. Ever.
4
Calculator modes
8
Simultaneous panels
79
Units to convert
$2.99
One-time unlock. Forever.
Features
Why CalcBoard Replaces Your Default Calculator
Multiple independent calculator panels running simultaneously, with shared state between them — something no mainstream calculator app offers. Stop switching between apps. Stop losing your place.
Shared Value Tray
Push a result from one panel to the shared tray and pull it into another. Transfer values between calculators instantly — no copying, no retyping, no lost numbers.
Named Variables
Save any value as a variable — type tax=0.0825 once, then use price*tax in any panel. Variables persist between sessions and work across every calculator mode.
Four Calculator Modes
Basic, scientific, programmer, and unit converter. Each panel picks its own mode independently. One app handles every type of calculation — from simple arithmetic to binary-to-hex conversion.
Full Calculation History
Every result is saved automatically. Bookmark important calculations and add custom labels; Premium unlocks your full history with search and CSV export. Never lose a calculation again.
Precise Decimal Arithmetic
Arbitrary-precision math with no floating-point rounding errors. 0.1 + 0.2 = 0.3 exactly, every time. Financial calculations, engineering formulas, and scientific computations you can trust.
Unit Converter (79 Units)
Instant conversion across 10 categories: length, mass, temperature, area, speed, time, data size, volume, energy, and pressure. Type a value and see the result instantly.
Control Center Quick Launch
Add CalcBoard to your iPhone's Control Center and launch it in a single tap from any screen. Faster than opening the app drawer.
Fully Customizable
8 color themes, 6 button styles (Classic, Glass, Circle, Edge-to-Edge, Soft, Minimal), light and dark mode, haptic and sound feedback. Make CalcBoard look and feel exactly how you want.
Built for Accessibility
VoiceOver labels on every key, WCAG AA contrast ratios, 48px minimum touch targets, and reduce-motion support. Designed for everyone from the start.
Calculator Modes
Four Calculator Modes. One App.
Set each panel to its own mode. Basic math in one, scientific in another, programmer in a third, unit converter in a fourth — all running simultaneously.
Basic Calculator
Standard arithmetic with full algebraic expression editing and arbitrary-precision results.
- Add, subtract, multiply, divide with correct order of operations
- Parentheses for complex expressions
- Casio-style percentage calculations (100+10% = 110)
- Undo, redo, and inline cursor editing
Scientific Calculator
Trigonometric, logarithmic, and exponential functions for students, engineers, and scientists.
- sin, cos, tan and inverse functions
- ln, log, e^x, 10^x
- Square root, cube root, factorial
- Constants: pi (π) and Euler's number (e)
Programmer Calculator
Binary, octal, decimal, and hexadecimal with bitwise operations for developers.
- BIN, OCT, DEC, HEX input and simultaneous display
- Bitwise AND, OR, XOR, NOT
- Left shift (<<) and right shift (>>)
- Hex digits A-F with full keyboard
Unit Converter
Instant conversion across 10 categories with 79 units. Results appear as you type.
- Free: Length, mass, temperature
- Premium: Area, speed, time, data, volume, energy, pressure
- 79 units across all categories
- Instant bidirectional conversion
Screenshots
See CalcBoard in Action
Real screenshots from the shipping app — multi-panel layouts, every calculator mode, and themes on iPhone and iPad.
How It Works
Start Calculating in Seconds
No account. No setup. No tutorial required. Open CalcBoard and you're already calculating.
Open CalcBoard
Two calculator panels are ready immediately. Start calculating with zero setup.
Choose Your Modes
Set each panel to Basic, Scientific, Programmer, or Unit Converter independently.
Calculate in Parallel
Work on multiple calculations at once. Each panel maintains its own independent state.
Share Results
Push values to the shared tray and pull them into any panel with a single tap.
Use Cases
Stop Juggling One Calculation at a Time
Standard calculator apps force you to do one calculation, write it down, clear, and start another. CalcBoard keeps everything visible at once.
Price Comparison
Two stores, two panels, instant side-by-side comparison
Homework Help
Multiple math problems visible and solvable simultaneously
Engineering
Convert units in one panel while calculating in another
Finance
Compare loan scenarios, budgets, or investments side by side
Software Development
Hex, binary, octal, and decimal conversions alongside math
Construction
Materials, measurements, and cost estimates all at once
Comparison
How CalcBoard Compares to Other Calculator Apps
Mainstream calculator apps handle one calculation at a time. CalcBoard runs up to 8 panels at once with cross-panel value sharing.
| Feature | Apple Calculator | PCalc | Calzy | CalcBoard (Free / $2.99) |
|---|---|---|---|---|
| Multiple simultaneous panels | — | — | — | Up to 8 |
| Shared value tray (cross-panel) | — | — | — | ✓ |
| Scientific mode | Landscape only | ✓ | ✓ | ✓ |
| Programmer mode (BIN/OCT/HEX) | — | ✓ | — | ✓ |
| Unit converter | Hundreds of units + currency | ✓ | — | 79 units, in its own panel |
| Calculation history | Basic (iOS 18+) | ✓ | ✓ | Search, labels + CSV export |
| Arbitrary-precision decimals | — | Not stated | Not stated | ✓ Confirmed |
| Customizable themes | — | ✓ | ✓ | 8 themes + 6 button styles |
| No ads | ✓ | ✓ | ✓ | ✓ |
| Price | Free (built-in) | Paid, one-time | Paid, one-time | Free / $2.99 one-time |
Comparison verified September 2026 against each app's current App Store listing. Apple's converter carries more units than CalcBoard's and adds live currency rates; CalcBoard's runs inside a panel next to a live calculation and works offline. Calzy's current version requires iOS 26 or later, where CalcBoard needs iOS 16. “Not stated” means that app's listing doesn't describe its arithmetic precision, so we don't claim it either way. Features and prices change — check the other apps' listings for their latest details.
Free on the web
Calculators You Can Use Right Now
No download, no sign-up, no ads — and nothing you type ever leaves your browser. These are complete tools, not demos.
Percentage Calculator
Percent of, percent change, and adding or subtracting a percentage — with the formula written out underneath.
Unit Price Comparison
Compare two or three package sizes and find out which is genuinely the better deal per unit.
Hex, Binary & Octal Converter
All four bases live at once, plus AND, OR, XOR, NOT and bit shifts — the web version of programmer mode.
Tip & Bill Splitter
Tip, total, and per-person share, with a round-up suggestion for settling up.
Discount Calculator
Sale price and real savings, including why stacked discounts never add up to their sum.
10 Unit Converters
Length, weight, temperature, volume, area, speed, time, data, energy and pressure — all 79 units the app converts.
Built for a particular job? Students · Developers · Engineers · Shopping · Small business · iPad · Mac
Pricing
No Subscriptions. No Ads. Ever.
Pay once, own it forever. CalcBoard will never show you an ad or charge a recurring fee. Your calculator shouldn't have a monthly bill.
One-Time Purchase
Premium Unlock
$2.99
Pay once. Yours forever. All future updates included.
- Up to 8 simultaneous calculator panels
- Shared value tray between panels
- Scientific and programmer calculator modes
- Full unit converter (10 categories, 79 units)
- Unlimited calculation history with search & CSV export
- 8 color themes & 6 button styles
Generous Free Tier
2 panels, basic mode, 3 converter categories, last 10 history entries. No ads. No time limits. No catch.
| Feature | Free | Premium ($2.99) |
|---|---|---|
| Basic calculator with expression editing | ✓ | ✓ |
| Scientific calculator mode | — | ✓ |
| Programmer calculator mode (BIN/OCT/DEC/HEX) | — | ✓ |
| Unit converter (basic: length, mass, temperature) | ✓ | ✓ |
| Unit converter (full: 10 categories, 79 units) | — | ✓ |
| Simultaneous calculator panels | Up to 2 | Up to 8 |
| Shared value tray between panels | — | ✓ |
| Calculation history | Last 10 | Full history + search |
| History export (CSV, copied to clipboard) | — | ✓ |
| Color themes & button styles | — | 8 themes + 6 styles |
| Ads | None | None |
FAQ
Frequently Asked Questions About CalcBoard
-
CalcBoard is a multi-panel calculator app for iPhone and iPad that lets you run up to 8 independent calculators on one screen simultaneously. Unlike the Apple Calculator or single-panel apps like Calzy, CalcBoard lets you see and work on multiple calculations at once, with a shared value tray to transfer results between panels. Each panel can run a different mode — basic, scientific, programmer, or unit converter.
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CalcBoard is free to download and use with no ads. The free version includes basic calculator mode, 2 panels, 3 unit converter categories (length, mass, temperature), and the last 10 history entries. Premium is a one-time purchase of $2.99 — no subscriptions, no recurring charges. There are no ads in either version, ever.
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Yes — that's exactly what CalcBoard is built for. You can run up to 8 independent calculator panels simultaneously on one screen. Each panel maintains its own calculation mode, state, and history. Free users get 2 panels; premium users get up to 8.
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Yes. CalcBoard's scientific mode (premium) includes trigonometric functions (sin, cos, tan and inverses), logarithms (ln, log), exponential functions (e^x, 10^x), square root, cube root, factorial, and constants (pi, e). Unlike the Apple Calculator, which only shows scientific mode in landscape, CalcBoard's scientific mode works in any orientation and can run alongside other calculator panels.
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Yes. CalcBoard's programmer mode (premium) supports binary (BIN), octal (OCT), decimal (DEC), and hexadecimal (HEX) input with all four bases displayed simultaneously. It includes bitwise AND, OR, XOR, NOT, and left/right bit shift operations. You can run programmer mode alongside basic or scientific panels to see decimal and hex results side by side.
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With Premium, use the shared value tray. Long-press the active panel to open the panel menu, then tap "Push to tray." The current result appears in the shared value tray. Switch to another panel and tap any value in the tray to paste it into that panel's expression. The tray shows each value's source panel name and can store up to 50 values.
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Open CalcBoard, go to Settings, then tap "Upgrade to Premium" and select "Restore Purchases." Make sure you're signed into the same Apple ID used for the original purchase. Your premium features will be restored immediately at no additional cost.
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Yes. CalcBoard uses exact decimal arithmetic instead of the IEEE 754 floating-point math that causes rounding errors in most calculators. This means 0.1 + 0.2 = 0.3 exactly. Financial calculations, engineering formulas, and everyday math all produce precise results you can trust.