# How to do proper number calculations in a Payload Format decoder? **URL:** \ **Category:** Application Development\ **Created:** [December 19, 2019, 4:13pm UTC](https://www.thethingsnetwork.org/forum/t/how-to-do-proper-number-calculations-in-a-payload-format-decoder/32799 "2019-12-19T16:13:54Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![arjanvanb](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/arjanvanb/32/46626_2.png) [@arjanvanb](https://www.thethingsnetwork.org/forum/u/arjanvanb)\ **Post date:** [December 19, 2019, 7:34pm UTC](https://www.thethingsnetwork.org/forum/t/how-to-do-proper-number-calculations-in-a-payload-format-decoder/32799/3 "2019-12-19T19:34:23Z")
There are quite a few things going on here: - Like @cslorabox already noted: JavaScript is not the same as Java. The payload formats in TTN Console use JavaScript (ECMAScript 5 to be precise). See also [MDN Web Docs](https://developer.mozilla.org/) to learn that. - **JavaScript’s decimal numbers are not exact.** - Apparently your device’s code is converting the decimal coordinates into positive integer numbers. However, when using bitwise operators in your decoder, then [JavaScript expects _signed_ 32 bits numbers](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators#Signed_32-bit_integers) using [two’s complement encoding](https://en.wikipedia.org/wiki/Two%27s_complement), hence allowing for numbers from -2,147,483,648 through 2,147,483,647. Finally, next time please don’t post screenshots for text: even after I cropped the image it’s hard to read on small devices, and it’s impossible to copy or quote. See [How do I format my forum post? [HowTo]](https://www.thethingsnetwork.org/forum/t/how-do-i-format-my-forum-post-howto/8735) Also, I doubt the output shown for longitude goes with the code that is shown…? --- _[View the full topic](https://www.thethingsnetwork.org/forum/t/how-to-do-proper-number-calculations-in-a-payload-format-decoder/32799)._