NUSUM, Calculator Notebook for Mac
A calculator notebook for your Mac. Type calculations in plain language, line by line, and see the answers beside them.
Download for Mac01What It Does
NUSUM works like a notepad calculator. Write a sum, a unit conversion or a currency amount on any line and the answer appears in the column beside it. Keep a Sheet for each project, add a total under a block, and reuse any answer with a click.
What you type in NUSUM stays on your Mac.
No account, no cloud, no tracking. The only thing NUSUM asks the internet for is exchange rates.
Plain Language Maths
Write sums the way you would say them: 15% off $240, half of 98, loan payments and compound interest.
Units and Conversions
Convert length, volume, weight, time, data sizes and CSS units: 300 ml to fl oz, 6 ft 2 in to cm.
Live Currency and Crypto
Convert world currencies and 22 cryptocurrencies, with rates refreshed every hour: $1,200 to EUR, 0.05 BTC in EUR.
Dates and Time Zones
Add days to a date, count workdays and convert times between cities: June 4 + 18 days, 6pm Lisbon in Tokyo.
Totals and References
Put Total or Average under a block of lines, or click any answer to reuse it further down.
Sheets, Folders and Pins
Keep as many Sheets as you like in the Drawer. Pin the ones you use most, tidy the rest into Folders, and search them by name or content.
02How to Install
Download the disk image and open it.
Drag NUSUM onto the Applications folder.
Open NUSUM. The first time, choose Open Anyway in System Settings, Privacy and Security.
macOS asks because NUSUM isn't notarised by Apple yet. Here's why it's safe, and how to check your download. To update, download the latest version and replace the copy in Applications. Your Sheets are kept in your Library folder, so they stay where they are.
03What's New
- See the download for the latest changes.
04Frequently Asked Questions
Is NUSUM Free?
Yes. NUSUM is free for personal use. There is no account to create and nothing to sign in to.
Which Macs Does NUSUM Run On?
NUSUM needs macOS 13 Ventura or later. It runs natively on both Apple silicon and Intel Macs.
Does NUSUM Work Offline?
Yes. Calculations, unit conversions, dates and time zones all work without a connection. Currency and crypto conversions need the internet to refresh rates, and when you are offline NUSUM uses the last rates it saved.
Is My Data Private?
What you type stays on your Mac. NUSUM has no account, no cloud and no tracking. The only thing it asks the internet for is exchange rates, and those requests never include anything from your Sheets.
Where Are My Sheets Saved?
Each Sheet is saved as a plain text file in your Library folder, shortly after each edit. Updating NUSUM leaves your Sheets where they are. NUSUM does not sync between Macs.
Why Does macOS Ask Me to Confirm When I Open NUSUM?
NUSUM isn't notarised by Apple yet, so macOS asks before opening it the first time. Open System Settings, go to Privacy and Security, and choose Open Anyway. Our Privacy and Safety page explains what NUSUM does and how to check that your download is genuine.
What Happened to SUMUP?
SUMUP is now NUSUM. It's the same app with a new name, and your Sheets, Folders and settings move across automatically the first time you open NUSUM.
How Do I Get Help or Send Feedback?
Email hello@arckhumlabs.xyz. Questions, bug reports and ideas for NUSUM are all welcome.