is it possible in manger to calculate individual sales invoice margin, or there is any report we can make to calculate margin from sales invoice or from customer?

I doubt it possible because sales invoice does not include cost of inventory within the form~~~

I think it is necessary to be able to calculate it, because in my case I have to calculate instantaneous margin on invoice to give customer cash discount. because I have multiple items and an invoice contains 10~60 items in one invoice and is difficult to calculate the exact margin at the time of invoice.

I think you can calculate using custom field, somewhere in this forum, check it out. I think the last time I read he used to calculate asset depreciation and hire purchase, which lubos implemented the simple arithmetic logic within custom field. Although other solution would be use spreadsheet program with template that can give you quick calculation and inventory margin listing.

You did not remember correctly, @acecombat2. Calculations can only be performed in built-in number fields. See Perform calculations in number fields | Manager. And you need to enter the numbers for the calculation yourself. Manager would not be able to insert the current average cost of an inventory item.

You can perform calculations on custom fields in a custom theme. See https://www.manager.io/guides/17115. However, you cannot be looking up cost of inventory in the process in order to calculate instantaneous margin on a line item, let alone total margin on an invoice.

@Ajmal.khan, discount determination is a pricing issue, not an accounting issue. The sales prices of your inventory items should be set to achieve a desired margin. Discount percentages can be determined in advance for each customer or category of customer, taking into account your normal margins.

thanks @Tut, line item margin is not my concern of course, but total invoice margin will be calculated with total of line item margins. its purely pricing issue but in my case I have to decide some instantaneous cash discounts off the case of pre-set prices and discounts, its common practice in my country. To get that margin is necessary to give that discount to the customer which will be added at the end of invoice.