fieldcalc — the free app that works offline

fieldcalc is free, and so is the app. Install it once and every one of the 100+ calculators keeps working with no signal — in a basement, a crawlspace, or a new build with no wifi. No account, no app store, nothing to pay and nothing to update: it updates itself.

Checking this device…

Why install it

  • Free, for good. No subscription, no in-app purchases, no trial that runs out.
  • Works offline. Every calculator is saved on your device, so a dead spot on site doesn't stop you.
  • One tap away. It opens from your home screen like any other app, with your most-used tools first.
  • Private. Your numbers are worked out on your device and never leave it.
  • Small. A few megabytes — about the size of a couple of photos.

iPhone or iPad

  1. Open fieldcalc.net in Safari (it has to be Safari — Chrome on iPhone can't install apps).
  2. Tap the Share button — the square with an arrow pointing up, at the bottom of the screen (top right on iPad).
  3. Scroll down and tap Add to Home Screen.
  4. Tap Add. The fieldcalc icon appears on your home screen.

Android

  1. Open fieldcalc.net in Chrome.
  2. Tap Install the free app (the button above or at the bottom of any page) — or tap the ⋮ menu, then Install app (some phones say Add to Home screen).
  3. Tap Install. The fieldcalc icon appears with your other apps.

Computer (Chrome or Edge)

  1. Open fieldcalc.net.
  2. Click the install icon at the right-hand end of the address bar (a screen with a small arrow), or click Install the free app.
  3. Click Install. fieldcalc opens in its own window and gets a desktop / Start-menu icon.

Check it works offline

  1. Open the app once while you have signal and wait a few seconds — the line at the top of this page says when everything is saved.
  2. Turn on airplane mode.
  3. Open the app and use any calculator. It works.

If a page ever says it hasn't been saved yet, open it once with signal and it's saved from then on.

Updates and removing it

There's nothing to update: when we add or fix a tool, the app picks it up the next time you open it with signal. To remove it, press and hold the icon and choose Remove (Android) or Remove App → Delete (iPhone). Nothing else is left behind.

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