# Using a formula in change node
**URL:** https://discourse.nodered.org/t/using-a-formula-in-change-node/86099
**Category:** General
**Created:** [3 March 2024 19:01 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099 "2024-03-03T19:01:18Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@k5map](https://discourse.nodered.org/u/k5map)
#### Post date: [3 March 2024 19:01 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/1 "2024-03-03T19:01:18Z")
Prior to v3.1.5, I used a formula in the change node to calculate a numerical value: (8192\*.66)
Now this formula is generating an error. Does anyone know how I can keep my formula but resolve the error? Please note the reason I am using a formula versus the result is so in the future if I need to go back to determine the two values which made up the result.
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [3 March 2024 19:44 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/2 "2024-03-03T19:44:37Z")
What error are you getting?
Can export the Change node and share it so we can see exactly how you have it configured?
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### Author:  [@k5map](https://discourse.nodered.org/u/k5map)
#### Post date: [3 March 2024 19:58 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/3 "2024-03-03T19:58:02Z")
When I click on Deploy, I get a pop up stating my node is not properly configured.
Here is a screenshot of my change node formula
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### Author:  [@christopher-lambe](https://discourse.nodered.org/u/christopher-lambe)
#### Post date: [3 March 2024 20:13 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/4 "2024-03-03T20:13:32Z")
Just use a JSONata expression and don't forget the zero before the decimal point.
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [3 March 2024 20:41 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/5 "2024-03-03T20:41:24Z")
Hi @k5map
In that screen shot, both of those fields are set to the `number` type. That type has never supported using formula.
I think you meant to set the to the `expression` type.
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### Author:  [@k5map](https://discourse.nodered.org/u/k5map)
#### Post date: [3 March 2024 23:11 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/6 "2024-03-03T23:11:32Z")
It has been working this year for well over a year... the only thing which has changed in the last 2 weeks is I upgraded to v3.1.5.
I'll change it to expression just so I can get it working again.
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [4 March 2024 09:08 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/7 "2024-03-04T09:08:33Z")
What version did you upgrade from?
I've tested this on each version going back to `3.0.2` and always get a value of `NaN` when I try to use a formula in the `number` type field.
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### Author:  [@k5map](https://discourse.nodered.org/u/k5map)
#### Post date: [4 March 2024 13:01 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/8 "2024-03-04T13:01:42Z")
I switched to using a JSON expression and the error has been resolved
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [2 June 2024 13:02 UTC](https://discourse.nodered.org/t/using-a-formula-in-change-node/86099/9 "2024-06-02T13:02:04Z")
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