# Calculation of variables (Logic or better Logic) **URL:** \ **Category:** Questions & Help\ **Tags:** flow\ **Created:** [December 27, 2020, 5:07pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913 "2020-12-27T17:07:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Menne\_Talsma](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/menne_talsma/32/8752_2.png) [@Menne\_Talsma](https://community.homey.app/u/Menne_Talsma)\ **Post date:** [December 27, 2020, 5:07pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/1 "2020-12-27T17:07:28Z")
Anyone an idea how to perform some advanced calculations fot variables? I would like to round the number at max 2 decimals i’ve done some trial-and-errorring with Logic and better logic Round(,2) $round(\ **Author:** ![Rocodamelshekima](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/rocodamelshekima/32/8209_2.png) [@Rocodamelshekima](https://community.homey.app/u/Rocodamelshekima)\ **Post date:** [December 27, 2020, 5:12pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/2 "2020-12-27T17:12:27Z") {{round (Tag inserted here,2)}} ---
**Author:** ![Menne\_Talsma](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/menne_talsma/32/8752_2.png) [@Menne\_Talsma](https://community.homey.app/u/Menne_Talsma)\ **Post date:** [December 28, 2020, 10:16pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/4 "2020-12-28T22:16:29Z")
WORKS!! Now the volume of the Top2000 on all the Sonos in the house increases or decreases nicely proportional anywhere I can find a tutorial for these kind of syntaxes? I’ve searched the community and Google but I get Lost ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [February 19, 2021, 1:57am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/5 "2021-02-19T01:57:32Z")
Same here. I searched my ass off, but very little examples… I’m looking for creating an array of names. Like {{random(round(1,10))}} results in a number between 1 and 10. How about a random pick between John, Ben, Julie, Jill? ---
**Author:** ![Edgar](https://avatars.discourse-cdn.com/v4/letter/e/b487fb/32.png) [@Edgar](https://community.homey.app/u/Edgar)\ **Post date:** [May 20, 2021, 8:10am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/6 "2021-05-20T08:10:38Z")
that doesn’t work anymore since last update: - [Logic] Changes rounding Logic variables from 0 to 2 decimals very nice the change, but unbelievable that they won’t tell how it works now… So, do u have an idea? i want round values with 1 decimal. ---
**Author:** ![Menne\_Talsma](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/menne_talsma/32/8752_2.png) [@Menne\_Talsma](https://community.homey.app/u/Menne_Talsma)\ **Post date:** [May 20, 2021, 8:50am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/7 "2021-05-20T08:50:47Z")
Ah, So that’s why this morning Sonos went from soft to Deaffening-loud within one click 😮 now my ears hurt ---
**Author:** ![JPe4619](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/jpe4619/32/9017_2.png) [@JPe4619](https://community.homey.app/u/JPe4619)\ **Post date:** [May 20, 2021, 11:21am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/8 "2021-05-20T11:21:51Z")
> [@Edgar](#): > > want round values with 1 decimal. {{round(value\*10)/10 }} ---
**Author:** ![Edgar](https://avatars.discourse-cdn.com/v4/letter/e/b487fb/32.png) [@Edgar](https://community.homey.app/u/Edgar)\ **Post date:** [May 20, 2021, 12:51pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/9 "2021-05-20T12:51:07Z")
Thnx! that works… but what is the new solution, any idea of that? why did they changed it? it was the correct way and now a workarround. ☹ ---
**Author:** ![Edgar](https://avatars.discourse-cdn.com/v4/letter/e/b487fb/32.png) [@Edgar](https://community.homey.app/u/Edgar)\ **Post date:** [May 20, 2021, 12:53pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/10 "2021-05-20T12:53:13Z")
o dear… i had that also in the beginning. my neighbours now hate me while it never happend again. that is because i limited the max volume in de sonos settings to max 50% ---
**Author:** ![Wout\_van\_den\_Dool](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wout_van_den_dool/32/391_2.png) [@Wout\_van\_den\_Dool](https://community.homey.app/u/Wout_van_den_Dool)\ **Post date:** [May 25, 2021, 5:19am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/11 "2021-05-25T05:19:36Z")
![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/c/e/cefbfbe7b184178a463c195cb2cc7929534c7b6e.png) What is going wrong and right here? The watermeter is writing its data in 486.555 Dutch. Where 555 are the liters…… thats why divided by 1000. Round by 3 numbers behind the comma ---
**Author:** ![Rocodamelshekima](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/rocodamelshekima/32/8209_2.png) [@Rocodamelshekima](https://community.homey.app/u/Rocodamelshekima)\ **Post date:** [May 25, 2021, 6:12am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/12 "2021-05-25T06:12:04Z")
![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/9/9/993b22ddca778678a6640b8ce2c8027c4fd66b6f.jpeg) Divided by 1000?? ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [May 25, 2021, 7:51am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/13 "2021-05-25T07:51:16Z")
But… why would you want to round liters to 3 decimals. Liters is the smallest unit in case of a watermeter So, the calculation needed looks like this: `{{[tag_eind]-[tag_begin]}}` Example: `486.755−486.555=0.2` When you want the number `0.2`(m³) in liter units, then all you have to do is multiply it with 1000: `{{([tag_eind]-[tag_begin])*1000}}` Example: `(486.755−486.555)*1000=200` ---
**Author:** ![DirkG](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/dirkg/32/118897_2.png) [@DirkG](https://community.homey.app/u/DirkG)\ **Post date:** [May 25, 2021, 8:20am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/14 "2021-05-25T08:20:06Z")
For people like me who can’t speak Dutch please translate it in English. Thx! ---
**Author:** ![Wout\_van\_den\_Dool](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wout_van_den_dool/32/391_2.png) [@Wout\_van\_den\_Dool](https://community.homey.app/u/Wout_van_den_Dool)\ **Post date:** [May 25, 2021, 9:21am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/15 "2021-05-25T09:21:18Z")
Ha Peter, dankjewel…. En inderdaad, die drie komma’s zijn onzin… ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [May 25, 2021, 10:16am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/16 "2021-05-25T10:16:21Z")
Whoops Dirk, I Englified my post 😉 Sometimes I’m writing in English in Dutch topics… I think it comes with age 🤣 ---
**Author:** ![Kai\_Engvik](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/kai_engvik/32/48687_2.png) [@Kai\_Engvik](https://community.homey.app/u/Kai_Engvik)\ **Post date:** [June 26, 2022, 5:08pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/17 "2022-06-26T17:08:46Z")
Works for me as of june 22 🙂 ---
**Author:** ![Edgar](https://avatars.discourse-cdn.com/v4/letter/e/b487fb/32.png) [@Edgar](https://community.homey.app/u/Edgar)\ **Post date:** [June 26, 2022, 8:56pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/18 "2022-06-26T20:56:24Z")
can u show? ---
**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\ **Post date:** [June 27, 2022, 12:57pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/21 "2022-06-27T12:57:50Z")
This is a way to round values to 0.1 or 0.5 or 0.01 or 0.25 Input value: ![Screenshot_20220627-144857_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/0/9/091b32c66910e076f5d64cebfd956ea1309d2ae5.jpeg) Flow: ![Screenshot_20220627-145246_Chrome](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/2/e/2e27f09e41c2a260e7e11fc1f3e8fbbc1bfd7fc9.jpeg) Output: ![Screenshot_20220627-144838_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/2/12ad4401d5a44e0efbb5f661f6c8ac28537d040e.jpeg) ---
**Author:** ![JPe4619](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/jpe4619/32/9017_2.png) [@JPe4619](https://community.homey.app/u/JPe4619)\ **Post date:** [June 27, 2022, 12:58pm UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/22 "2022-06-27T12:58:50Z")
> [@JPe4619](#): > > {{round(value\*10)/10 }} For 2 decimals, use: {{round(value\*100)/100}} ---
**Author:** ![Peter\_Bittner](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_bittner/32/16698_2.png) [@Peter\_Bittner](https://community.homey.app/u/Peter_Bittner)\ **Post date:** [July 8, 2023, 4:57am UTC](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913/23 "2023-07-08T04:57:39Z")
I am trying to work out how to use better logic variables versus logic variables. It looks like Better Logic variables are seperate. I want to set a variable to the result of subtracting one Tag from another Tag. I can do this with Better Logic but then I can’t work out how to access the Better Logic variable from other flow cards. [Next page](https://community.homey.app/t/calculation-of-variables-logic-or-better-logic/39913.md?page=2)