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

    • Copy field information to clipboard

      I need to be able to transfer some field information in to the clipboard, so that I can then paste it in to our helpdesk system. Is there a way I could add a button to a detail report that does this?

    • Issuing reconciling a bank statement

      HELP! I'm trying to reconcile a bank statement. The prior month reconciled perfectly. Beginning balance is correct yet I'm off by the same amount each time. Both myself and my office manager, separately and together, have tried to complete this reconciliation

    • Unknown table or alias 'A1'

      I would like to create a subquery but i am getting the following error: Unknown table or alias 'A1' used in select query. This is the sql statement:  SELECT A1.active_paying_customers, A1.active_trial_customers, A1.new_paying_signup, date(A1.date_active_customers), 

    • Detect and ignore bots in visitors

      The SalesIQ visitor numbers are basically useless to us because there is no bot detection. We get the same bots coming in from the same countries looking at the same pages every day. It can't be that difficult to tell the difference between an actual

    • Add Real-Time Microphone Audio-Level Indicator During Screen Recording

      Hi Zoho WorkDrive Team, Hope you are doing well. We would like to request an important enhancement to the Zoho WorkDrive screen-recording experience. Current Limitation: During a recording session, there is no visual indication that the microphone is

    • Zero Personalization of the File Sharing Experience

      By now (2025) this is the maximum level of personalization available for a Zoho sharing link. We gently asked Zoho if we could modify at least the background, and they replied that it cannot be customized. We're truly disappointed – and surprised every

    • Two factor authentication for helpdesk users

      The company i work for wants use the helpdesk site in Zoho desk, as a place for their distribution partners to ask question and look for information about our product. The things there is suppose to go up there is somewhat confidential between my company

    • Kiosk can't merge picklist or multiselect

      There is no ability to load a multiselect or picklikst field into a kiosk with the values that have been previously selected. So, I essentially have 3 unacceptable options: 1.)Load the value into a text string and include instructions like this: "Picklist

    • AGE field from DATE OF BIRTH Field.

      HI! I have a field called date of birth in my CRM (LEADS, CONTACT etc…)     How can I know the AGE today   I would like to create a field AGE. I now how to create a field but I don´t which calculation (CUSTOM FUCTION) to make ¿ANY HELP?

    • How to update/remove file in zoho creator widgets using javascript API

      Hi Team, I have developed a widget which allows inserting and updating records I have file upload field with multiple file upload. Now while doing insert form record, I am using uploadFile API to upload files for that record. I am using updateRecord API

    • Announcing new features in Trident for Windows (v.1.34.4.0)

      Hello Community! Trident for Windows just got better! With this update we have features that make your daily work easier and more efficient. We've added some features that are exclusive to our app and we're sure you'll find them useful. Let’s dive into

    • Report Hover Setting

      Would be great if we will able to show information to the user while hovering a record in a report.

    • Vertical images displayed as horizontal

      Some pictures that originally are in vertical position are displayed in horizontal after the upload. It seems that system rotates them by 90 degrees. How can I fix this issue?

    • Zoho Desk iOS app update: Saved filters and sort options

      Hello everyone! Saved filters created on the web(desk.zoho.com) for tickets are now accessible on the Zoho Desk iOS app. You can easily rename, delete, or clear filters on the go. We have also introduced Sort options on the ticket listing screen, allowing

    • Big Things Just Dropped in the SalesIQ Universe: Top Upgrades You’ll Love in Nova’25

      Nova'25 has landed, and it’s packed with meaningful upgrades to help you engage smarter, work faster, and scale with ease. Whether you're into proactive messaging, smarter automation, or better admin control, there's something here for everyone. Here's

    • Time Entries in Analytics

      I am trying to import a zoho sheet into zoho analytics. In my sheets one of the columns has "time Entries" in this "format HH:MM am/pm" example 11:00 PM. After import, i noticed that analytics converted the time to "00 Jan 1900 23:00:00".. how do i maintain

    • Amazon invoice in Zoho Books

      I have just made my first few sales on Amazon India. Amazon Seller account generates invoices for the sales made on Amazon. These invoices are sent to customers also. Now when I was only making offline sales, I used to create Invoices in Zoho Book. Now

    • Zoho Creator Upcoming Updates - November 2025

      Hello everyone, Welcome to your monthly roundup of new features and enhancements! We hope you've already taken a look at Release Projection 2—it details the features coming your way for the rest of the year. And this month, we're excited to start rolling

    • Zoho Webinar + HubSpot : Simplifiez la gestion de vos données de webinaires

      Les webinaires sont aujourd’hui essentiels pour interagir avec vos prospects et vos clients. Cependant, la gestion des données entre plusieurs plateformes peut vite devenir complexe. Grâce à la nouvelle intégration entre Zoho Webinar et HubSpot, vos outils

    • I am trying to give access to one of our educators access to 3 forms in Zoho and she is not able to view the data - Access issue

      Hi Team, When I try to provide read access to one of our educators on Zoho for Pre-training , post training and Impact survey forms submit form access which also allows them to read , it does not show them data

    • How to book GST paid in zoho books

      hi, i am a new user to Zoho books and not able to book GST paid in books, kindly suggest how i can book it in books. thanks, siddharth

    • PUNJAB NATIONAL BANK (CORPORATE) INDIA - NOT AVAILABLE IN BANKING

      Dear sir, Kindly fix it. PUNJAB NATIONAL BANK (INDIA) is available but PUNJAB NATIONAL BANK (CORPORATE) is not available. Kindly enable this banking since we need to categorize the entries. Regards, Sanjay Jena email id/ user id : travewithmerchant@

    • Is it possible to create a word cloud chart in ZoHo Analystics?

      Hi there, I have a volume of transaction text that I would like to analyse using word cloud (or other approcah to detect and present word frequency in a dataset). For example, I have 50,000 records describing menu items in restaurants. I want to be able

    • Kaizen #216 - Actions APIs : Email Notifications

      Welcome to another week of Kaizen! For the last three weeks, we have been discussing Zylker's workflows. We successfully updated a dormant workflow, built a new one from the ground up and more. But our work is not finished—these automated processes are

    • Facturation électronique 2026 - obligation dès le 1er septembre 2026

      Bonjour, Je me permets de réagir à divers posts publiés ici et là concernant le projet de E-Invoicing, dans le cadre de la facturation électronique prévue très prochainement. Dans le cadre du passage à la facturation électronique pour les entreprises,

    • Your bot just got smarter: AI-Powered routing that reads between the lines

      What if your bot could tell the difference? Between a visitor who just needs a quick answer, someone actively comparing options, and a frustrated customer one click away from leaving? Most bots can't. They deliver the same response to everyone, missing

    • Weekly Tips : Master Keyboard Shortcuts in Zoho Mail

      If you spend a lot of time managing emails, switching between your mouse and keyboard can slow you down. Whether you are replying to clients, organizing your inbox, or searching for messages, every second counts. So, how can you streamline your email

    • Introducing custom lookup fields in the Tickets, Contacts, and Accounts modules

      Hello all, We are excited to announce a new enhancement that will empower you to further customize the Tickets, Contacts, and Accounts modules. Now, you will be able to create custom lookup fields in your Tickets, Contacts, and Accounts layouts for more

    • DKIM cannot be enabled for the domain as no verified default selector present

      Can't get the DKIM working. May you please check my account (nksy.us) to see what's wrong?

    • Contacts per department

      Hello, Is it possible to limit Contacts to a Department? Thanks

    • Collections Management: #3 Tackling Payment Failures

      Sam refreshed the dashboard. "Payment failed". Same customer. Same subscription. This is happening for the third time. He sends a usual email: "Your renewal payment failed again. Could you please check and retry?" A couple of days passed, and there was

    • How do I increase the email attachment size in Zoho CRM ?

      It looks like I'm limited to 10MB when sending an attachment using the email widget on a record in Zoho CRM. Is there a way to increase the size? Or can I use some other tool? From what I'm reading online, I'm maxed out at 10MB. Any insight would be greatly

    • WhatsApp Channels in Zoho Campaigns

      Now that Meta has opened WhatsApp Channels globally, will you add it to Zoho Campaigns? It's another top channel for marketing communications as email and SMS. Thanks.

    • Zoho sign and creator error message {"code":9043,"error_param":"Checked by","message":"Extra key found","status":"failure"}

      Good day, I receive the error message: {"code":9043,"error_param":"Checked by","message":"Extra key found","status":"failure"} when running below code from creator to sign, void TestForSign(int ID) { //Fetch Template Details (Optional, for dynamic mapping)

    • Download a writer template as .docx instead of .pdf.

      I have been trying to implement a feature to download a writer template as a .docx and got it working partly but it isn't good. Earlier I checked our code and I saw openurl("https://crm.zoho.com/crm/org121314/specific/Template.do?action=print&step=pdfPreview&id="

    • Allow the usage of Multi-Select fields as the primary field on "Layout Rules"

      We want to force our users to enter some explanation strings when a multi-select field has been utilized. I can't understand the reason for the usage restriction of Multi-Select fields as a primary field. This is a simple "Display hidden mandatory field

    • Extract Archived Projects using Zoho Projects API

      In my organization we archive the projects when they are already completed, charged, invoiced, so that only those that are still pending process remain active. I need to access all projects (active and archived) from an external system, but the API v3

    • Ask the Experts: Five-hour live Q&A session with Zoho WorkDrive product experts

      Have questions about WorkDrive 5.0? Let’s talk! We recently launched Zoho WorkDrive 5.0, packed with powerful updates to help your team work smarter, stay secure, and get more value from your business content. From content-centric workflows and AI-powered

    • File upload support for subforms

      Dear All, Subforms help you add and track data related to your CRM records. We've always supported most of the commonly used field types in subforms, so as to cater to your business requirements. Now we're happy to extend support to file upload fields.

    • Circular record relationship in CRM

      Given there is a lookup in custom module Transactions creating a related list on the chosen Contact record. I. e. a lookup field on Transactions module points to Contacts. The related list on a Contact record can thus have have many transaction records.

    • Next Page