# Build a calculator or use external script

**URL:** <https://community.noloco.io/t/build-a-calculator-or-use-external-script/1647>\
**Category:** Ask for Help\
**Tags:** feature-request\
**Created:** [January 24, 2025, 3:13pm UTC](https://community.noloco.io/t/build-a-calculator-or-use-external-script/1647 "2025-01-24T15:13:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![garyGHL](https://dub1.discourse-cdn.com/flex005/user_avatar/community.noloco.io/garyghl/32/555_2.png) [@garyGHL](https://community.noloco.io/u/garyGHL)\
**Post date:** [January 24, 2025, 3:13pm UTC](https://community.noloco.io/t/build-a-calculator-or-use-external-script/1647/1 "2025-01-24T15:13:54Z")

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Hi there, I am trying to build some mortgage calculators for my app but now realise I cant use a formula field in another formula (Can I?)

So, formulafield1 result + formulafield2 result =

As I cant do that, I thought I’d embed an external script but that doesn’t seem to work either. Is there an option to add code as below, it displays blank currently.

 ![image](https://europe1.discourse-cdn.com/flex005/uploads/noloco/original/2X/9/918fbebee51dc106f3fc130bcaa9edef4eb28013.png)

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**Author:** ![lukebranford](https://dub1.discourse-cdn.com/flex005/user_avatar/community.noloco.io/lukebranford/32/32_2.png) [@lukebranford](https://community.noloco.io/u/lukebranford)\
**Post date:** [January 24, 2025, 3:20pm UTC](https://community.noloco.io/t/build-a-calculator-or-use-external-script/1647/2 "2025-01-24T15:20:43Z")

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Hey Gary, I’m certainly no dev but have got scripts working in iframes with some help, so should work in theory. Looking at my scripts they all end with , not sure if that’s relevant?

And formula within formula doesn’t work as you say, be awesome if it did!

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**Author:** ![garyGHL](https://dub1.discourse-cdn.com/flex005/user_avatar/community.noloco.io/garyghl/32/555_2.png) [@garyGHL](https://community.noloco.io/u/garyGHL)\
**Post date:** [January 24, 2025, 3:33pm UTC](https://community.noloco.io/t/build-a-calculator-or-use-external-script/1647/3 "2025-01-24T15:33:30Z")

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Thanks Luke, yes the preference would be to build my own calcs but not to be. Yet 😀

Managed to get the external working by using the url only without the script.

Cheers