Setting Up the ProfitMetrics Profit Variable in Server-Side GTM

What You Need

Before configuring the variable, make sure you have the following ready.

To request your API key from the ProfitMetrics support team, please feel free to use the following template:

Hi ProfitMetrics,

Please create a server-side GTM variable API key for the website below: 

Public ID:
URL: https://example.com

Installing the Template

The variable ships as a custom template file (.tpl) which you import into your server-side GTM workspace.

1. Download the template file from this Google Drive link.
2. In server-side GTM, go to Templates → Variable Templates → New.
3. In the template editor, open the menu (three dots, top right) and choose Import. Select the downloaded .tpl file.
4. Save the template and close the editor.
5. Go to Variables → New → User-Defined Variable, then select ProfitMetrics - Profit from the custom variable types.

Profitmetrics data

This is the main configuration block. It connects the variable to your ProfitMetrics account and provides the order-level fields used in the profit calculation.

VAT information

These checkboxes describe whether the values in your purchase event already include VAT. The variable strips VAT before sending values to ProfitMetrics, so the settings need to match what your platform actually sends.

The Vat rate (%) field only appears when at least one of the three checkboxes above is enabled. If your VAT settings are wrong, ProfitMetrics will calculate incorrect profit. If you are unsure, check a sample order against your platform admin.

Event data the variable reads automatically

The variable reads the following fields directly from the purchase event in your server container. You do not need to map them manually unless you want to override one of them.

If transaction_id is missing from the event, the variable returns nothing and the calling tag does not receive a value.

Overwrite event data (optional)

Use this section if you need to replace any of the standard fields before they are sent to ProfitMetrics — for example, if your event uses a different identifier as the order ID, or if you want to hash an email before sending.

Each row has two columns: Field (a dropdown of supported field names) and Value (a literal string or a GTM variable reference). Values set here always take priority over the auto-read event data.

Profit metrics Order overrides (optional)

Use this section to manually override individual cost fields or the calculated profit on a per-order basis. This is useful when you have known costs that ProfitMetrics cannot derive from the order itself.

Currency

By default, the variable uses the currency code from the purchase event. If you need to override it — for example, when your store reports values in one currency but you want ProfitMetrics to treat them as another — enter a three-letter currency code in the Output currency field (e.g. USD, EUR, GBP). Leave the field blank if the event's currency is correct.

Set up an Estimated profit fallback variable

The Profit variable returns a live value from ProfitMetrics. For tags where you want a backup value available — for example, during initial setup, or as an approximate value if the live calculation is unavailable — create an Estimated profit variable based on your store's average margin.

1. In server-side GTM, go to Templates → Variable Templates and import the Deduct percentage template from the Community Template Gallery.
2. Go to Variables → New → User-Defined Variable and select Deduct percentage. Name it Estimated profit.
3. Set Input number to your order value variable.
4. Set Percentage to your store's average margin. For a 35% margin, enter 35.
5. Leave Input includes percentage unchecked.

You can now reference {{Estimated profit}} anywhere a backup profit value is useful.

Create a value transformation

A server-side transformation runs before the affected tags fire and rewrites fields on the incoming event. This avoids hard-coding the variable reference into each conversion tag.

1. In server-side GTM, go to Transformations → New → Augment Event.
2. Name the transformation Gross profit value transformation.
3. Under Parameters to augment, add a row with Name set to value and Value set to {{ProfitMetrics - Profit}}{% endraw}.
4. Under Affected tags, select only the tags that should report profit as the conversion value — for example, a dedicated Google Ads Gross Profit conversion tag. Do not apply it to tags that should still receive revenue.
5. Save the transformation.

Configure the destination tag

In the conversion tag that should use profit as its value (e.g. the Google Ads Gross Profit conversion tag):

• Leave Conversion value and Transaction ID blank.
• Make sure the tag is set to read these fields from the incoming event data automatically (they normally do this by default with a standard Google Analytics event stream format).

By the time the tag fires, the transformation has already replaced the event's value with the calculated profit, so the tag reports profit instead of revenue. The Profit variable resolves once per request, so multiple tags reading it in the same request receive the same value without triggering a second calculation.

Troubleshooting

If the variable returns no value or an unexpected value, enable Log to console in the variable settings and run the request again in the server-side GTM Preview mode. The console output shows the data being sent and the response received.

For anything not covered here, contact support@profitmetrics.io.

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For anything not covered here, contact support@profitmetrics.io.