🧮 Ghost Calc

A calculator that types its answer into any window – search below to find what you need
🔍
⭐ Insert
Insert — the reason Ghost Calc exists SIGNATURE
The Insert → button types the current display value into whichever window had focus before Ghost Calc opened. Open Notepad, click into it, open Ghost Calc from the tray, work out 250 * 0.15, click Insert — 37.5 appears at your cursor in Notepad. No copy, no paste, no alt-tab.
Typical flow: 1. Click into your notes / email / spreadsheet 2. Open Ghost Calc from the tray 3. Do the calculation 4. Click "Insert →" (or press the Ctrl+Enter shortcut if enabled) 5. The answer lands right where you were typing
⭐ Insert
Target Window Label
Just below the display, a small grey label reads "Target: Untitled — Notepad". It shows exactly which window Insert will send to. Check it before clicking — no more "oops, sent 36 to my boss's Slack." The target updates whenever you click away and back.
⭐ Insert
Copy (and Copy-on-Insert)
The Copy button sends the display value to the clipboard — useful when you want to paste it manually, or send it somewhere Insert can't reach. There's also a Settings toggle: "Also copy the answer to clipboard on Insert." On by default, so every Insert also leaves the value on the clipboard. Belt and braces.
⭐ Insert
Close After Insert (toggle)
By default Ghost Calc stays open after an Insert, so you can do more calculations in one sitting. A Settings toggle changes that: turn "Close Ghost Calc after Insert" on and the window hides itself the moment the answer lands. Perfect for one-shot calculations.
🧮 Calculator
Standard Calculator
Familiar Windows-Calculator layout: memory row (MC, MR, MS, M+, M−), clear functions (←, CE, C, ±, √), digits and operators in the middle, and a tall = button on the right. Every key you know, nothing you don't.
🧮 Calculator
Expression Line
Above the big display, a smaller grey line shows your whole calculation chain as you build it: 15 + 6 × 9. Just like Windows Calculator. When you press =, the chain clears and the big display shows the result.
🧮 Calculator
The Sister Panel FUN
If your expression gets so long that the top line overflows, Ghost Calc grows a second panel to the left — a sister window that continues the display. Type 1+2+3+4+5+6+7+8+9+10+11+12+13+14+15 and watch her slide in. When you press C or =, she slides back home. Purely cosmetic, entirely delightful.
🧮 Calculator
Percent ( Shift+5 or the % button )
Matches Windows Calculator's behaviour: 100 + 10% gives 110 (add 10% of the left operand), and 100 - 25% gives 75 (subtract 25% of the left operand). 50 * 10% gives 5. If no operator is pending, 50% alone gives 0.5.
🧮 Calculator
Memory Buttons
MS stores the display value, MR recalls it, MC clears it, M+ and M− add or subtract the display from memory. The same memory model as any pocket calculator.
🧮 Calculator
√, 1/x, ±, CE, C, ←
square root, 1/x reciprocal, ± sign flip, CE clears just the current entry, C clears everything, backspaces one digit. Divide-by-zero shows Error and refuses to crash — you just press C and carry on.
🧮 Calculator
Digit Grouping
Optional — off by default. Turn on in Settings and the display shows 1,234,567 instead of 1234567. Purely visual; the underlying value is unaffected.
⌨️ Keyboard
Keyboard Support
Everything works from either the main keyboard or the numpad:
  • 09 — digits (both rows)
  • + - * / — operators (numpad or Shift-modified main row)
  • . — decimal point
  • Enter or = — equals
  • Backspace — backspace one digit
  • Esc — clear all
  • Shift+5 — percent
📐 Worksheets
The "Fill Any Four, Solve the Fifth" Pattern
Every worksheet in Ghost Calc follows one simple rule: fill in all but one field, click Calculate, and the missing field gets solved. No "solve for rate" dropdown, no mode switch — the shape of what you left blank tells the calculator what to do.
Example: Mortgage Principal = 250000 Rate = 5.25 Term = 30 ← Monthly payment blank → Calculate → Monthly payment solves to 1379.17 Or go the other way — leave Rate blank instead: → Calculate → Rate solves to 5.25%
Only one worksheet is open at a time — clicking another in the View menu swaps them. Ctrl+F4 (or View → Basic) folds everything back to just the calculator.
📐 Worksheets
Mortgage Repayment
Four fields: Principal, Rate (% per year), Term (years), Monthly payment. Any three known → the fourth is solved.
Reverse-check a loan offer: Principal = 250000 Term = 30 Payment = 1379.17 Rate = (blank) → Calculate → Rate = 5.25% per year
Rate-solving uses an iterative method under the hood, so it's exact to 4 decimal places.
📐 Worksheets
Fixed Deposit
Lump-sum savings that grows untouched. Five fields: Principal, Rate, Term (years), Compounding (Daily / Monthly / Quarterly / Semi-annually / Annually), and Maturity. Fill any four, solve the fifth.
Principal = 10000 Rate = 5 Term = 5 Compounding = Annually Maturity = (blank) → Calculate → Maturity = 12,762.82
Same inputs with Daily compounding instead of Annually → 12,840.03. That's the daily-compounding advantage, made visible.
📐 Worksheets
Recurring Saver
Savings where you deposit money every month and start with a lump sum. Five numeric fields: Initial principal, Monthly deposit, Rate, Term, Maturity — plus a Compounding dropdown that defaults to Daily, because that's what high-yield savings accounts use.
Initial principal = 10000 Monthly deposit = 500 Rate = 5 Term = 3 Compounding = Daily → Calculate → Maturity ≈ 30,998 Or leave Monthly deposit blank to find out how much you'd need to deposit each month to reach a target.
The math blends fixed-deposit growth on the initial principal with annuity accumulation on the deposits — matching how real savings accounts actually work.
📐 Worksheets
Unit Conversion
Eight categories, dozens of units, live conversion as you type. Pick a category, pick From, pick To, type a value — the result appears instantly. The Swap button flips From and To in one click.
Categories: • Length — m, km, cm, mm, mi, yd, ft, in • Weight — kg, g, mg, lb, oz, st, t • Temperature — °C, °F, K • Volume — L, mL, m³, US gal, qt, pt, cup, fl oz • Area — m², km², ft², yd², acres, hectares • Speed — m/s, km/h, mph, knots, ft/s • Time — s, min, h, days, weeks • Data — bytes, KB, MB, GB, TB, bits
Temperature gets proper offset handling (0°C = 32°F = 273.15K). Everything else is straightforward factor multiplication.
📐 Worksheets
Date Calculation
Two modes, chosen from a dropdown:
  • Difference — pick two dates, get the gap as "3 years, 2 months, 14 days" plus the total day count
  • Add / Subtract — pick a start date, an amount, and a unit (Days, Weeks, Months, Years), choose Add or Subtract, and get the resulting date
Add/Subtract correctly handles calendar arithmetic — "1 month from Jan 31" gives Feb 28/29, not March 3.
🗂️ Menus
View Menu
The only menu that matters. Basic (Ctrl+F4) folds every worksheet back to just the calculator. Below that: Mortgage, Fixed deposit, Recurring saver, Unit conversion, Date calculation. A radio dot shows which worksheet is currently open; clicking the same one again closes it.
🗂️ Menus
Basic — the fold-up escape hatch
One command, one purpose: close every open worksheet and return to the plain calculator. No hunting for X buttons. Ctrl+F4 or View → Basic, and you're home.
🗂️ Menus
Edit Menu
One item: Copy display (Ctrl+C). Same as the Copy button below the keypad.
🖥️ Tray
Tray Icon
Ghost Calc lives in the notification area. Double-click the tray icon to bring the window forward — this is how you capture the target window (whatever was focused before the click becomes the Insert destination). Right-click for the menu: Open Calculator, Settings, Help Contents, About, Exit.
⚙️ Settings
Settings
Four toggles, saved to ghostcalc.ini:
  • Close Ghost Calc after Insert — off by default; on = window hides after the answer lands
  • Also copy the answer to clipboard on Insert — on by default; belt-and-braces backup
  • Always on top — on by default; keeps Calc above your other windows
  • Digit grouping — off by default; on = 1,234,567 instead of 1234567
💾 Files
Settings File: ghostcalc.ini
Sits next to the exe. Stores the four toggles. Editable by hand if you prefer that to the Settings dialog — changes take effect next launch.
💾 Files
Fully Portable
No registry keys, no AppData clutter. Everything Ghost Calc needs sits in its own folder. Copy the folder to a USB stick and it works anywhere with .NET Framework 4.x installed.
💾 Files
Single Instance
Only one copy of Ghost Calc can run at a time. Launching again just brings the existing window forward.
👻 Bundle
Coexisting with Ghost Phrases
Ghost Phrases (the text expander) runs in the tray alongside Ghost Calc. Both watch the keyboard, but Phrases recognises when Ghost Calc has focus and steps aside so the two never fight over keystrokes. Type 100+10% in Calc while Phrases is running — it just works. The moment you click away to another app, Phrases resumes expanding normally.
⚙️ Advanced
Elevated Windows Caveat
Insert uses SetForegroundWindow + SendInput. If the target app is running as Administrator and Ghost Calc is not, Windows may block the foreground switch. Run Ghost Calc as Administrator too, or copy the value and paste it manually.
⚙️ Advanced
Offline & Private
Ghost Calc never touches the network. No analytics, no update check, no cloud. Everything runs locally on your machine.
👻 Bundle
The Ghost Bundle Family
Ghost Calc is one of six small utilities under the Ghost Bundle umbrella:
  • Ghost Reader — distraction-free reader
  • Ghost Stamp — file timestamping & signing
  • Ghost Cast — multi-voice script studio
  • Ghost Notes — hierarchical notebook
  • Ghost Phrases — text expander
  • Ghost Calc — calculator that types its answer into any window (you are here)
Six utilities. One family. Each does one thing well and stays out of your way. 💚
✨ No features match your search.

🧮 About Ghost Calc

Ghost Calc is a small calculator that does something no other Windows calculator does: it can type its own answer into whatever you were working on. Open it from the tray, do your arithmetic, click Insert — and the number lands at your cursor, in Notepad, an email, a spreadsheet, anywhere. Underneath it's a proper Windows-Calculator-style keypad with memory buttons, percent, square root, and a proper expression line. Push further and you'll find five worksheets — mortgage, fixed deposit, recurring saver, unit conversion, and date calculation — all built around the same "fill any four, solve the fifth" idea. No accounts, no cloud, no nagging. Ghost Calc is free, and it always will be. 💚