Apple’s stock Calculator app that comes preloaded on iPhone and iPod touch is apparently plagued with an issue that causes input to be lost if you type too quickly.

This appears to be unique to iOS 11.

According to a long thread on Reddit (via Loop Insight), the issue appears to stem from the fact that the app blocks all input during the animation for the button fades.

This causes it to not register key taps until the animation finishes.

If I had to guess, I’d say this is an iOS problem rather than an isolated Calculator issue. Although iOS 11 betas did allow for taps to register before a UI animation finished playing, that behavior changed in the commercial release of iOS 11.

I can confirm that this is not fixed in the most recent beta of iOS 11.1. I tried Calculator on iOS 10.x and there was no input lag whatsoever.

Clearly this is yet another design oversight in iOS 11 that may or may not be addressed in one of the future iOS software updates. You can, of course, tell Apple how dissatisfied you are with this by filing a bug report at

Have you noticed this Calculator issue before?

When I first encountered it, I thought maybe it had something to do with upgrading to iOS 11 versus performing a clean install of iOS. However, later I did reinstall iOS 11 from scratch and the issue still persists. That being said, I was never too concerned about the input lag because I use the excellent PCalc app for all my math needs.

Have you noticed this bug yet?

And while we’re at it, what’s your favorite Calculator replacement?

  • Simone


  • It’s called a slugbug

    • nonchalont

      To force consumers to upgrade their phones.

      • Garrett Driskill

        that doesn’t even make sense. this problem persists on the iPhone 8 and 8 plus too, also iPhone X if they don’t release an update for it.

  • David Gow

    No issues here. BUT ever since I’ve updated to 11 my safari is out of date according to some web sites and is real slow. Says I need to update safari

  • nonchalont

    Yup, fact that Apple places bugs into their software to slow down older phones in order to force consumers to upgrade. Shame on you Apple!

    • lemieuxfan67

      Except, the same issue is happening with my iPhone 8 Plus.

  • Yep yep, known issue throughout all beta releases of IOS 11. Apple didn’t take it seriously when it’s been reported. Hopefully with some more exposure they’ll fix it.

  • Jose Gonzalez

    I use the stock calculator a lot and have noticed this issue every time I use it after updating to iOS 11. Very annoying.

  • CuBoy531

    When it lags, use your brain. Stop relying on calculator for everything. What’s 2+2? You can type really fast with that.

  • Felipe Queiroz Drumond

    Anyone facing problems with WhatsApp keyboard? Sometimes it is misplaced, sometimes it doesn’t even show! (iOS 11)

  • Garrett Driskill

    I can confirm that this is was a bug since the first iOS 11.0 beta.

  • ElephantLeg

    When it lags, use your brain. Stop relying on calculator for everything. What’s 2+2? You can type really fast with that.

    • Kevin Andres

      Yeah, I’ll just use my brain next time I’m calculate the square root of the log of 523.1. Pretty trivial stuff. *rolls eyes*

    • Dyx

      Typical Apple fanboy lol

      • Bebacotan

        the stupid ones

  • Robert Mathews

    I haven’t had any lag issues with ios 11 at all, even this calculator problem. I have an iPhone 6s ios 11.0.3

  • lewis

    To force consumers to upgrade their phones.

  • techfreak23

    Never noticed this. I just tested on my 7 and didn’t notice any issues. I’m on the latest public beta for 11.1… my keyboard, however, was having lag issues in the first few betas of 11.1, but this last one seems to have cleared it up for the most part.

  • eXoguti097

    I was trying to add up some monthly payments yesterday for a total and the calculator messed up about 4 times before I started typing the numbers almost once per second to make sure they would register. It’s very frustrating, it’s not like I was blazing through the numbers either.

  • Benedict

    Anyway! Good to have the world’s fastest phone.. 😉

  • Benedict

    Shows again the advantage of updating system apps also via Play Store… Would have been fixed by now. Happy waiting for another system update…

  • jacjustjac

    I remember this being an issue back on iOS 9. Type too fast and it doesn’t read the modifier. It seems to just be even WORSE on iOS 11, but it’s always been a problem for me when I type too fast.