Slate: Calculator

In-app purchases
Content rating
Everyone
500+
Downloads
Content rating
Everyone
Learn more
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image
Screenshot image

About this app

Slate is eight everyday calculators in one, dressed in chalk on a slate board: keys that click like they mean it, and everything you actually need, nothing you don't.

EIGHT TOOLS, ONE KEYPAD
• Calculator: basic for everyday sums; one tap opens the scientific keys: trig and inverses, logs, roots, powers, factorials, π and e, degrees or radians. Percent works the way desk calculators always have (50 + 10% is 55), and the tape above the display remembers recent results, so tap one to use it again.
• Percent: discounts, markups, tips-of-the-tongue "what percent of what" sums.
• Date: days between dates, add or subtract days, work out an age.
• Tip: split the bill fairly, down to the cent. (Pro)
• Units: length, weight, volume, temperature and more. (Pro)
• Loan: repayments and total interest at a glance. (Pro)
• GST: add it to a quote or pull it out of a total, at any rate. (Pro)
• Exchange: convert currencies on published reference rates, and keep the last table on the phone. (Pro)

Every tool runs on the same skinned keypad, and the system keyboard never appears.

EVERY SUM REMEMBERED
Slate keeps the calculations you finish, newest first. Tap one and it loads straight back into the tool that worked it out, ready to change. Clearing the list is two taps.

SKINS THAT CHANGE EVERYTHING
Slate ships in chalk. Slate Pro re-dresses every tool: Ledger's paper and ink, Terminal's green phosphor glow, Porcelain's clean white, Ember's warm coals, Drift's dusk violet, Blueprint's cyanotype lines. Every skin pairs with its own key sounds: Typewriter (with a carriage bell on equals), Beeps, Droplets, Woodblock, Hush and Abacus.

CAST IT
Put your working on the big screen: cast to a TV and Slate mirrors whichever tool is up, same numbers, same skin, while your phone stays the keypad. Walk away and an idle cast tidies itself up after a few minutes.

CALM ABOUT EVERYTHING ELSE
• No ads · No accounts · No subscriptions
• The calculator tools work offline: everything ships inside the app.
• Slate uses the network for Exchange's published reference rates, for the store's billing for the one-time purchase, and for casting to your TV if you use it.

PAY ONCE, OWN IT
Slate is complete without paying: the full basic and scientific calculator, Percent, Date, the tape, the history, the chalk board and its key sounds. Slate Pro is a single one-time purchase that unlocks the other five tools and every skin and sound set, including the ones we add later. Pay once, own it forever, and no subscription, ever.

From Zone7 Studios, maker of Ethereal, Brume, Sylph and Lore.
Eight calculators on one chalk slate: percent, date, tip, loan, GST, exchange.
Updated on
Aug 30, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
    Learn more about how developers declare sharing
  • This app may collect these data types
    App activity, App info and performance, and Device or other IDs
  • Data is encrypted in transit
  • Data can’t be deleted

What’s new

New in 1.4
- The navigation bar now stays visible. Full screen mode is available in Settings.
- history added to calculator
- Bug fixes