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

    • Recent Topics

    • New 2026 Application Themes

      Love the new themes - shame you can't get a little more granular with the colours, ie 3 different colours so one for the dropdown menu background. Also, I did have our logo above the application name but it appears you can't change logo placement position

    • Zoho Desk: Macro to assign Ticket to self

      Hello, We are using macros in Zoho Desk to set some fields and send a response. I would also like to assign the ticket to myself (or whoever applies the macro). I can only set a fixed agent in the macro, so I would have to create one for every agent.

    • Turn off Knowlege Base Follow options and Follower lists

      Is there a way to hide or turn off the option in the Knowledge Base for users to follow specific departments/categories/sections/articles? If not, is there a way to turn off the public list of followers for each of those things? Otherwise, customer names

    • Enterprise Data management solutions

      I'm on the hunt for the perfect Data management solution for my organization. I've been doing a ton of research across different websites, but honestly, it's just left me more confused! A friend suggested I check here, so I'm hoping someone can point

    • New Feature: Audit Log in Zoho Bookings

      Greetings from the Zoho Bookings team! We’re excited to introduce Audit Log, a new feature designed to help you track all key actions related to your appointments. With Audit Log, you can maintain transparency, strengthen security, and ensure accountability.

    • Automated Task reminder

      First question: If a task does not have a reminder set, will it still send an email notification that the task is due today? If not, how can I set up an automated reminder to send the task owner an email that it is due on a certain date?

    • Zoho Support - contract notifications

      Hi, I have a few questions about using Zoho support. Is there a way to add custom contract notifications like (90 days before expiry send notification e-mail to agent and customer, then another 60 days before expiry and another 30 days.). And is it possible

    • Kaizen #230 - Smart Discount-Based Quote Approvals Using CRM Functions and Approval Process

      Hello everyone! Welcome back to the Kaizen series! Discount approvals are a standard part of sales governance. Most organizations need something like this: Discount % Required Action < 10% Auto-approve 10–19.99% Sales Manager approval ≥ 20% VP Sales approval

    • How to create a new Batch and update Stock via Inventory?

      Hi everyone, We are building an automation where a user enters batch details (Batch Number, Mfg Date, Expiry, and Quantity) into a Custom Module. I need this to trigger an API call to Zoho Inventory to: Create the new batch for the item. Increase the

    • OAuth2 Scope Error - Incorrectly defaulting to CRM instead of Analytics.

      Hello Zoho Team, I am trying to connect n8n to Zoho Analytics API V2 for a simple automation project. Despite using the correct Analytics-specific scopes, my OAuth handshake is failing with a CRM-related error. The Problem: The authorization screen shows:

    • Is it possible to create a meeting in Zoho Crm which automatically creates a Google Meet link?

      We are using Google's own "Zoho CRM for Google" integration and also Zoho's "Google Apps Sync" tools, but none of them provide us with the ability to create a meeting in Zoho CRM that then adds a Google Meet link into the meeting. Is this something that

    • Trigger a Workflow Function if an Attachment (Related List) has been added

      Hello, I have a Case Module with a related list which is Attachment. I want to trigger a workflow if I added an attachment. I've seen some topics about this in zoho community that was posted few months ago and based on the answers, there is no trigger

    • How can I link Products in a Deal Subform to the Products Module

      Hello, I have a pricing subform on our Deals page and use a lookup field to associate a product with each line. I want to be able to look at a product page within the Products module and see a list of the deals connected to that product. I have this working

    • Email Field Validation Incorrectly Rejects RFC-Compliant Addresses (Forward Slashes)

      I've encountered a validation issue with Zoho Creator's Email field that rejects RFC-compliant email addresses containing forward slashes, and I'm hoping the Zoho team can address this in a future update. The Issue When entering an email address containing

    • Call result pop up on call when call ends

      I’d like to be able to create a pop up that appears after a call has finished that allows me to select the Call Result. I'm using RingCentral. I have seen from a previous, now locked, thread on Zoho Cares that this capability has been implemented, but

    • ZOHO.CRM.UI.Record.open not working properly

      I have a Zoho CRM Widget and in it I have a block where it will open the blocks Meeting like below block.addEventListener("click", () => { ZOHO.CRM.UI.Record.open({ Entity: "Events", RecordID: meeting.id }).catch(err => { console.error("Open record failed:",

    • ZOHO.CRM.UI.Record.open not working properly

      I have a Zoho CRM Widget and in it I have a block where it will open the blocks Meeting like below block.addEventListener("click", () => { ZOHO.CRM.UI.Record.open({ Entity: "Events", RecordID: meeting.id }).catch(err => { console.error("Open record failed:",

    • Payment system for donations management

      I manage an organization where we receive donations from payers. Hence, there is no need to first create invoices and then create payments received against the invoices. What are the recommended best practices to do this in ZohoBooks?

    • Recording the deducted TDS on advance received from Customer (Zoho Books India)

      Hi, How can we record the tds that has been deducted by my customer for the advance that he has paid to me. 1) My customer has paid Rs 10000 to me as advance (Rs 9800 as cash and deducted Rs 200 as TDS). I am not able to record the tds that has been deducted

    • Changing Account Type in Chart of Accounts

      Does anyone know how to change/edit the account type for an Account name in Chart of Accounts. Zoho will not let me do this for some reason

    • Bulk bank rule creatioin

      Hi team, I am exploring Option to create a multiple bank rule. Could please suggest the option to implement this?

    • The Social Wall: January 2026

      Hello everyone, We’re back with the first edition of The Social Wall of 2026. There’s a lot planned for the year ahead, and we’re starting with a few useful features and improvements released in January to help you get started. Create a GBP in Social

    • Zoho books aide

      Bonjour, je rencontre un problème avec Zoho Books. J’ai effectué une demande de support via l’interface prévue à cet effet, mais je n’ai jamais de retour. Je ne reçois ni email de confirmation, ni information concernant la prise en charge de ma demande,

    • Smart Data, Smarter Contracts — Ensuring Consistency Between Metadata and Documents

      In contract management, data accuracy is not just a nice-to-have—it is essential. A single mismatch between what your system shows and what is written in the contract can ripple into approval delays, compliance risks, and broken trust in your data. Imagine

    • Join Zoho Meeting only via Web browser and not with Zoho Meeting App

      Dear Zoho team, according to the documentation [1], Zoho Meeting only offers web view for Chrome and Firefox on a desktop. For other browsers and devices, participants can only join a Zoho Meaning with the Zoho Meeting App installed. This is a big hurdle

    • CRM gets location smart with the all new Map View: visualize records, locate records within any radius, and more

      Hello all, We've introduced a new way to work with location data in Zoho CRM: the Map View. Instead of scrolling through endless lists, your records now appear as pins on a map. Built on top of the all-new address field and powered by Mappls (MapMyIndia),

    • Move email between inboxes?

      Is it possible to move emails from one team inbox to another? We would like to be able to have a single "catch-all" inbox for incoming requests, and then move the email to the appropriate department inbox. I was hoping we would be able to accomplish this

    • Updating records through Zoho Sheets View doesn't update timeline or trigger workflow rules

      I have noticed that when i update a series of record with the zoho sheets view (see here http://d.pr/i/ahnR) it doesn't update timeline history or trigger workflow rules. I am using it in the Deals module. Looking forward for some more info. Denis

    • Manage control over Microsoft Office 365 integrations with profile-based sync permissions

      Greetings all, Previously, all users in Zoho CRM had access to enable Microsoft integrations (Calendar, Contacts, and Tasks) in their accounts, regardless of their profile type. Users with administrator profiles can now manage profile-based permissions

    • inability to use different primary address on invoice per location

      my company operates in two different locations with different email address. The problems then is the inability to edit the primary to suite the invoice for the second location.

    • AI Search and Record Retrieval Inside Zoho Creator – Is This Possible?

      Is it possible to integrate an AI assistant into Zoho Creator that can intelligently search, retrieve, and analyze records within the application’s forms and reports? Can AI access and query existing Creator data securely using Deluge or APIs to provide

    • Rename Service Report

      Some of our customers are requesting the name of the service report PDF to be in a specific format, for example, instead of REP-001.PDF some are requesting to include their name like customername.pdf. is that possible?

    • AI Search and Record Retrieval Inside Zoho Creator – Is This Possible?

      Is it possible to integrate an AI assistant into Zoho Creator that can intelligently search, retrieve, and analyze records within the application’s forms and reports? Can AI access and query existing Creator data securely using Deluge or APIs to provide

    • Scheduled AU Data Center Database Version Upgrade for Zoho Forms

      Dear Zoho Forms' users, We would like to update you on a scheduled AU Data Center database version upgrade for Zoho Forms. Find the schedule below: Migration window: Sunday, 22nd February 2026 12.00 AM to 12.30 AM AEDT This migration is a part of our

    • Cannot get code to work with v2.mergeAndStore!

      Please can someone help me pass subform items into a repeating mail merge table row using v2.mergeAndStore? I have a mail merge template created in Writer and stored in Workdrive. This template is referenced by a custom CRM function which merges all of

    • Hotmail is blocking the zoho mail IP

      Greetings, Since last Tuesday (5 days ago today) I wrote to Zoho support and I still haven't received a single response (Ticket ID: 2056917). Is this how you treat people who pay for your email service? I am making this public so that those who want to

    • Zoho Bookings and Survey Integration through Flow

      I am trying to set up flows where once an appointment is marked as completed in Zoho Bookings, the applicable survey form would be sent to the customer. Problem is, I cannot customise flows wherein if Consultation A is completed, Survey Form A would be

    • Zoho CRM Community Digest - December 2025 | Part 2

      Hello Everyone! During the final weeks of December, Zoho CRM introduced updates that not only enhanced product capabilities but also offered deeper guidance through Kaizen posts. This section highlights what was released and shared in the last two weeks

    • CRUD actions for Resources via API

      Hello, is it possible to perform CRUD actions through the API for Resources? We want to create a sync from Zoho CRM Car record to Bookings resources to create availabilities for Car bookings. For Test drives, not only the sales person needs to be available,

    • Kaizen #186 : Client Script Support for Subforms

      Hello everyone! Welcome back to another exciting Kaizen post on Client Script! In this edition, we’re taking a closer look at Client Script Support for Subforms with the help of the following scenario. " Zylker, a manufacturing company, uses the "Orders"

    • Next Page