TapeCalc 2: AutoHotkey v2 Calculator With an Editable Paper Tape
Every step lands on a tape you can edit, plus 4,900+ unit conversions. Windows exe and full AutoHotkey v2 source included.
Back in 2002, PC Magazine put out a little utility called TapeCalc. It was a desk calculator with a paper tape, like an old adding machine. Every number you typed showed up on the tape, and you could go back and fix a typo three steps ago without starting over.
I’ve kept a copy of it around ever since. Holy cow, that was almost 25 years ago! 😃
So we rebuilt it in AutoHotkey v2. Same idea, modern dark window, and a whole lot more unit conversions.
Have you ever added up a column of numbers in Windows Calculator, gotten a weird total, and had NO idea which number you fat-fingered? Yeah. Me too. That’s exactly the problem a tape solves.

See Every Step, Fix Any Step
The keypad is on the left and the tape is on the right. Every number, every operator and every total lands on the tape as its own line.
- Fix a typo without retyping: double-click any line, change the number or the operator, and everything below it re-calculates.
- Delete a step: right-click a line and it’s gone. The totals update by themselves.
- Undo and Clear: Undo walks back one change at a time. Clear starts a fresh tape, and Undo brings the old one back if you change your mind.
- Percent that makes sense: 200 + 10% = 220, and 200 × 10% = 20.
- Memory keys: MS, MR, M+, M− and MC, with an M indicator so you know something is stored.
- Number formats: floating point, 2, 3 or 4 fixed decimals, or currency. It only changes how numbers look, never the math.
4,900+ Unit Conversions, Right on the Tape
This is where it gets fun. Type a number, press Ctrl+T (or click the Convert button), and the converted value goes on the tape like any other step. The tape shows both units, like millimeters → inches, so you always know what happened.
The cool thing is that conversions are part of the calculation. Convert 254 millimeters to inches, then multiply by 3. Change the 254 later and the conversion AND the total update.
Need different units? Click Units… and start typing. Type “fahr” and you’re looking at Fahrenheit. Type “cup” and you get every cup in the list. There are 28 categories:

Length • Area • Astronomical • Volume • Weight • Kitchen • Temperature • Time • Storage & memory • Speed • Energy • Power • Pressure • Angle • Data rate • Typography • Resolution • Torque • Flow rate • Frequency • Force • Ratio • Counting • Illuminance • Density • Fuel economy • EV efficiency • Baking
Take Your Work to Excel
Click Save and the whole tape goes to a tab-delimited file. Or hit Ctrl+C and paste it straight into Excel. Each column lands in its own cell, at full precision. No retyping.
What You Get
- TapeCalc2.exe: double-click and go. No install needed.
- The full AutoHotkey v2 source: see exactly how it works and change whatever you want.
- A 16-page user guide (PDF and HTML) covering every key, shortcut and conversion.
| Requirement | Details |
|---|---|
| Windows | Windows 10 or 11 (64-bit) |
| To run the exe | Nothing else. AutoHotkey does not need to be installed. |
| To run the source | AutoHotkey v2.0.2 or newer |
Get TapeCalc 2
For less than a cup of coffee you get the exe, the full source and the user guide. If you’ve ever re-added a column of numbers because you couldn’t find the typo, this will pay for itself the first afternoon. 🚀
Price: $4.99
How about you? Do you still keep a calculator with a tape around, or have you been squinting at Windows Calculator all these years? 😊

