Now with 12 stunning themes and 4 real desk layouts. Switch between Citizen Pro, GST Pro and more — with precise GST, markup and memory calculations.

Citizen Calculator is a precision-built calculator for iPhone that works exactly the way a real Citizen desktop calculator does — not a simplified phone calculator, but a complete professional tool you can rely on every day.

Real calculator logic

Operations run left to right as you type. Press 2 + 3 x 4 and get 20, not 14 — exactly like a physical desk calculator. Constant equals lets you repeat the last operation by pressing = again. Every calculation is done in pure decimal math, so 0.1 + 0.2 gives 0.3, never a floating-point surprise.

Built-in GST calculator

Add or remove GST at rates of 3%, 5%, 12%, 18%, and 28% with a single key. Switch rates instantly from the display chip without opening settings. Perfect for shopkeepers, accountants, freelancers, and anyone who works with Indian GST every day.

Five keypad layouts

Each layout arrives with its own signature theme, so the calculator looks cohesive the moment you switch.

Choose the layout that matches how you work:

• Citizen Pro: the standard desktop arrangement with all functions at hand
• Citizen Desk: the classic desk layout with a tall equals key and separate function column
• GST Pro: dedicated GST keys front and centre for tax-heavy workflows
• Plus: a wide-format layout optimised for adding long columns of numbers

Twelve themes

Citizen Classic, Desk Silver, Desk Carbon, Midnight Pro, Neon Night, Ocean Depth, Rose Quartz, Royal Gold, Retro LCD, Forest, Sunset Glass, and Minimal Light. Every theme applies a complete visual makeover — background, display, all key colours, shadows, and glow effects.

Professional calculator functions

• Memory: M+, M-, MR, and MC. M+ and M- complete any pending operation before storing, just like a real Citizen.
• Grand Total (GT): every equals result is automatically accumulated. Press GT to recall, press GT twice to clear.
• Markup (MU): calculate the selling price for a target gross margin in one step.
• Percent: completes with the pending operator — 200 + 10% gives 220.
• Square Root: keeps the pending operator active, so 9 + sqrt 16 = gives 13.
• Swipe left or right on the display to delete the last digit.
• Long-press AC to reset everything including memory and grand total.

Physical key feel

Every key press and release has a distinct haptic tick tuned to its role — light for numbers, firm for operators, rigid for equals. An optional key-click sound plays on every press. Keys animate with a press-and-bounce to feel like real physical switches.

Number formats

Switch between international formatting (1,234,567) and Indian formatting (12,34,567) in settings. The display updates instantly.

Calculation history

Every completed calculation is saved automatically. Tap any entry to load the result straight back to the display. History is preserved between app launches.

Privacy

No account required. No analytics. No ads. All data — history, memory, total — is stored only on your device.