Function 58: Custom calculation in item table of invoices (2 fields)

Function 58: Custom calculation in item table of invoices (2 fields)



Hello everyone, and welcome back to our series!

In Zoho Books, the Item Amount in invoices is calculated by multiplying the Quantity and Rate fields. Previously, we shared a function to include a custom field in this calculation.  Today, we are taking it a step further to make it even more versatile for various business needs. Instead of just one custom field, you can include two custom fields to determine the Item Amount.

Item Amount = Custom Field 1 × Custom Field 2 × Rate × Quantity

Consider Mr. John Hector, who runs a steel production plant. He processes orders for steel sheets according to their dimensions. For accurate billing, he can utilize today's function. When creating the invoice, John can enter the length and width of each steel sheet into the custom fields and specify the number of sheets ordered, and the rate per square foot in the default fields. The function will automatically calculate the Item Amount using this formula:

Item Amount = Length × Width × Quantity × Rate



Prerequisites: 

1. Create a Connection named "zbooks" to successfully execute the function. You can watch the GIF attached below to know how to create the connection. 



2. Create the third (Length) and fourth (Width) variables as item-level custom fields (Decimal type) to be displayed in the sales transactions.



3. Similarly, create another custom field called " Unit Rate" to be displayed in the item table. The purpose of this custom field is to store the original sales rate of the line item. 



Custom Function:

Navigate to Settings -> Automation -> Workflow Actions -> Custom Functions -> +New Custom Function -> Add the function code from this GitHub link -> Save.

Workflow Rule:  

Go to Settings -> Automation -> Workflow Rules -> +New Workflow Rule and set up the workflow rule as shown below:-





In the final step of this workflow rule, associate the custom function you created and then hit Save.

Here's how the function will work:

The custom function will be executed once the invoice is saved. Initially, it copies the original sales rate to the Unit Rate (Custom) field. Then, it multiplies Length × Width × Unit Rate and populates the result in the Rate (Default) field. Following this, Zoho Books calculates Rate (Default field) × Quantity and fills the result in the Amount field.

Note: If you wish to hide the "Rate" - default field at the template level, go to Settings > Customisation > PDF Templates > Invoices > Edit > Table > Disable the checkbox for Rate field > Save. Now, the Custom Field 1 (Length), Custom Field 2 (Width), Unit Rate (Custom Field), Quantity and the Amount field will be displayed on the invoices.



If you have to incorporate two extra values into your Item Amount calculation, this function is perfect for you. For further customization or assistance, please reach out to our Support team at support[at]zohobooks[dot]com. We're here to help!

Regards,
Shireen Farhana
Zoho Cares

    Nederlandse Hulpbronnen


      • Recent Topics

      • Changing the owner of a call

        Am I correct in my conclusion that I cannot change the owner of a call in Zoho? The field does not show up in the screen, nor can I make it show up as the systems does not give me that option. I cannot "mass update" it either. I tried it, but Zoho refuses to change the name of the owner. Please help out: how do I change the owner of a call.
      • Unified Notes View For Seamless Collaboration

        To facilitate better coordination among different departments and team members, the notes added to a record can now be accessed in all its associated records. With this, team members, from customer service representatives to field technicians, can easily
      • Remove Profiles from "Forecast" Module

        How can I remove Profiles from My forecast Module? Image Below The only revenue generators are the VP's, and the Estimation Managers, and the Estimators subordinate to the Est. Managers. How can I remove the unused Profiles? Its frustrating to see them
      • Integrate Excel or Zoho Sheet functions / calculations to CRM product module

        Hello Community, I hope someone more experienced can help me with this question. Our price / payment plan calculations are in an Excel spreadsheet and I would like to use all those functions / calculations in my Products module. So when we send a quote
      • Sync CRM Contacts to USER'S contacts on Office 365

        I can see that the O365 sync is transferring contacts backwards and forwards between Zoho CRM and Office365. But it has created a separate address book in Office 365 called "Zoho CRM Contacts". This address book is not used by Office/Outlook's email function
      • Uplifted homepage experience

        Editions: All editions. Availability update: 17th February 2026: All editions in the CA and SA DC | JP DC (Free, Standard and Professional editions) 23 February 2026: JP (All Editions) | AU, CN (Free, Standard, Professional editions) 27 February 2026:
      • Logging Out of FSM

        I have tried to log out of FSM app of the last person and it will not let me do so. I need to log in to my account.
      • Restoring records from the recycle bin programatically

        Background I'm working on a piece of software to automate conversion of Leads into Deals based on order status from my company's website. The process is mostly complete, right now I'm just working on handling a few edge cases to ensure data integrity.
      • Does Zoho Learn integrate with Zoho Connect,People,Workdrive,Project,Desk?

        Can we propose Zoho LEarn as a centralised Knowledge Portal tool that can get synched with the other Zoho products and serve as a central Knowledge repository?
      • All new Address Field in Zoho CRM: maintain structured and accurate address inputs

        Availability Update: 29 September 2025: It's currently available for all new sign-ups and for existing Zoho CRM orgs which are in the Professional edition exclusively for IN DC users. 2 March 2026: Available to users in all DCs except US and EU DC. Latest
      • Create static subforms in Zoho CRM: streamline data entry with pre-defined values

        Last modified on (9 July, 2025): This feature was available in early access and is currently being rolled out to customers in phases. Currently available for users in the the AU, CA, and SA DCs. It will be enabled for the remaining DCs in the next couple
      • SalesIQ Identity Update for Logged In Wordpress User

        Hey folks, SalesIQ does not automatically detect when a visitor logs in to WordPress and update their identity to match. For example, if a client of ours visits the site and logs in, SalesIQ will not track them correctly by default. The Solution The solution
      • Feature Request – Conditional Visitor Information Request in Zoho SalesIQ

        We would like to request the ability to conditionally ask for visitor details based on the communication channel used in Zoho SalesIQ. Specifically: When a visitor initiates a conversation through the live chat widget on the website, we want to continue
      • Add zoho calendar to google calendar

        Hi I keep seeing instructions on how to sync Zoho CRM calendar with google calendar but no instructions on how to view Zoho calendar in my google calendar.
      • Promote a layout to standard so I can delete one layout

        Similar to this and many other topics: https://help.zoho.com/portal/en/community/topic/set-layout-as-standard The problem, every model has a standard layout, which is what we use most of the time... But as the business grows and evolves we may have to
      • Workdrive on Android - Gallery Photo Backups

        Hello, Is there any way of backing up the photos on my android phone directly to a specific folder on Workdrive? Assuming i have the workdrive app installed on the phone in question. Emma
      • Auto sync Photo storage

        Hello I am new to Zoho Workdrive and was wondering if the is a way of automatically syncing photos on my Android phone to my workdrive as want to move away from Google? Thanks
      • Is anyone experience missing functions in the new UI until hard refresh?

        The set of functions including search is almost always missing upon loading an app in the new UI. If you refresh, the functions return. (see second screenshot) Anyone else experiencing this?
      • Conversion Rate – Won Deals over Assigned Prospects

        Hello, I would like assistance configuring a KPI in Zoho Analytics titled: Objective of the calculation: Number of Won Deals divided by Total number of assigned prospects (not only converted prospects). Important clarification: The denominator must include
      • Not receiving New Ticket Emails

        Hello! The company I work for uses the Zoho ticketing system, however, I've noticed I'm not receiving email notifications when new tickets are published. I have admin rights to see these tickets on Zoho Desk and respond to them, but am not receiving the
      • Can't update a field on a parent form from a child form's On Success workflow

        Title: Can't update a field on a parent form from a child form's On Success workflow Hi everyone, I'm building a simple Golf Lesson Tracker app and I'm stuck on what should be a basic operation — updating a number field on a parent form when a child form
      • Approvals in Zoho Creator

        Hi, This is Surya, in one of  my creator application I have a form called job posting, and I created an approval process for that form. When a user submits that form the record directly adding to that form's report, even it is in the review for approval.
      • Upload from Zoho Creator File Upload field to OpenAI Vector Store

        I’ve struggled for quite a while to get this working properly. For a long time we relied on Azure Functions as a workaround to handle file transfers between Zoho Creator and OpenAI Vector Stores. It worked, but added unnecessary infrastructure and complexity.
      • Allow Admin to Configure Report > More Options Button

        As an Admin, I want to configure the options of the Report > More Options button to improve UX and reduce Developer overhead. See attached screenshot. Original question posted here: https://help.zoho.com/portal/en/community/topic/modify-standard-rep
      • Calendar start time limit

        Hi all, Has anyone found a magical way to filter calendar reports to start from, let's say 8:00, and not 0:00? Or at least to auto scroll there like Google Calendar for example?
      • Enable Free External Collaboration on Notecards in Zoho Notebook

        Hi Zoho Notebook Team, I would like to suggest a feature enhancement regarding external collaboration in Zoho Notebook. Currently, we can share notes with external users, and they are able to view the content without any issue. However, when these external
      • EU Problem

        Hi all, we've been facing issues with the Europe data center for two days. It's starting to disrupt our daily workflow. Any word on when this will be resolved?
      • How can I clone my website in order to try new templates?

        I want to try a new template for my existing Zoho website without the risk of changing the current site or accidentally publishing the wrong template. Therefore I thought a 'clone website'-option should be somewhere, but I can't find it. How do I try
      • Is it possible to update multiple work items at once?

        Hi, Is it possible to update the statuses/release tags of multiple work items at once? I came across this thread that says it's not possible at the moment, but it was related to the Sprints mobile app. Does this feature not exist in the website as well?
      • Custom Module Missing from Roles & Permissions List

        Hi Zoho Community, I created a new Custom Module in Zoho Expense. The module is fully built and I can see it in the Module Builder (Settings > Customization > Modules). However, I am unable to deploy this to my users because the module does not appear
      • Custom view inconsistencies

        Why is "is not" missing from criteria, along with other comparison operators ??? It makes it almost impossible to build required custom views, I don't want "void" invoices listed & why on earth would "Void" invoices be showing when the criteria includes
      • Need Customer Item Inward Module along with QC

        Need Customer Item Inward Module along with QC 1. Using Transfer Orders hit the item balance sheet 2. Items without inventory it becomes difficult for tracking purpose. 3. Custom Modules become tedious to capture multiple items, item subforms are not
      • Zoho CRM Quotes – Subform and PDF/Writer Limitations

        Hello, I am encountering the following limitations in Zoho CRM Quotes: Custom product images cannot be uploaded in the subform – the image upload field cannot be added; only the file upload field is available. File upload placeholders cannot be used in
      • Apple Messages for Business in Omnichannel communications?

        Hello, Apple launched "Apple Messages for Business" but Zoho CRM or Zoho Desk don't appear in the list of possible integrators. Zoho already promotes https://www.zoho.com/crm/omnichannel.html Omni Channel integration, but Apple Messages does not yet appear.
      • Possible to Turn Off Automatic Notifications for Approvals?

        Hello, This is another question regarding the approval process. First a bit of background: Each of our accounts is assigned a rank based on potential sales. In Zoho, the account rank field is a drop-down with the 5 rank levels and is located on the account
      • Will be possible to create a merge mail template for products?

        Hi, we would need to create a mail merge template for products (native) module. Will be possibile? or do you have a smart solutions to merge products data with a mail merge? thanks Chris
      • Maximum incoming email (attachment size) limit

        I see that the maximum size of received emails can now be set to 20MB, however I'd still like to see it be larger. It's embarrassing when a client sends me an email with a large attachment and I can't receive it. 50, even 100 MB seems reasonable these
      • [Free Webinar] Learning Table Series - Multi-currency management in Zoho Creator

        Hello everyone, We’re excited to invite you to another edition of the Learning Table Series webinar. As you may already know, we've moved to a purpose-based approach in the Learning Table Series this year. Each session now focuses on how a Zoho Creator
      • Outlook/Hotmail Blocking Zoho SMTP IPs (S3150)

        We are currently facing a serious deliverability issue with Zoho SMTP while sending transactional OTP emails for our production application. Emails sent to Outlook / Hotmail addresses are being rejected with the following error: 550 - 5.7.1 Unfortunately,
      • Outlook is blocking incoming mail

        Outlook is blocking all emails sent from the Zoho server. ERROR CODE :550 - 5.7.1 Unfortunately, messages from [136.143.169.51] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). It looks
      • Next Page