Calculate and Set Mobile Bid Modifiers


The purpose of this AdWords Script is to bring AdWords performance on mobile devices in line with performance on desktop + tablet. With the introduction of Enhanced Campaigns in Google AdWords, it is no longer possible to have a separate campaign for mobile; now mobile is part of a regular campaign and bids are controlled with a mobile bid multiplier that can be set from -100% to 300%. This script sets the mobile bid adjustment to bring mobile performance in line with the results of desktop+tablet.

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Example Use Cases

  • Calculate and set the campaign level mobile bid modifier for all your AdWords campaigns
  • Calculate the ad group level mobile bid modifiers and email a spreadsheet with recommended changes that can be applied through AdWords Editor


This script was written by Russell Savage of As such, this script is part of the free section of our AdWords Scripts Library.

This script uses the methodology explained by Kohki Yamaguchi on to automate setting the appropriate mobile bid modifier.


Settings and Customizations

Set the date range to use for calculating multipliers. You can also use the format YYYYMMDD,YYYYMMDD

  • DATE_RANGE: tells the script the date range to include in the calculation. E.g. 'LAST_30_DAYS'. You can also use the format 'YYYYMMDD,YYYYMMDD'.
  • LEVEL: Set to Campaign if you want to calculate at the Campaign level and have the changes made by the script or set to AdGroup if you want to calculate at the AdGroup level and make the changes manually in AdWords Editor. Making changes at the Ad Group level is not supported by AdWords Scripts as of the time of publication. When that becomes available, we'll update this script.
  • TO: set to the email addresses that should receive the file with recommended changes if running the script at the AdGroup level. E.g. ['',''].
  • METRIC: Set to ROAS to use Return On Ad Spend for the calulcation or set to RPC to use Revenue Per Click for the calculation. To understand the difference refer to the explanation on
  • MINIMUM_BID_ADJUSTMENT: The lowest allowed bid adjustment to set or suggest, e.g. 0.5 for a -50% bid modifier.
  • MAXIMUM_BID_ADJUSTMENT:  The highest allowed bid adjustment to set or suggest, e.g. 3 for a +300% bid modifier.
  • DECIMAL_PLACES: Use this to adjust the number of decimal places to keep for calculations, e.g. 3.

Under The Hood

This script looks for the difference in ROAS or RPC performance between mobile and desktop+tablet. It analyzes keyword level data and applies either a cost or click-based weighting to the suggested multiplier.

  • Keywords that have no conversions are excluded from any calculations.
  • For keywords that have mobile conversions but NO desktop+tablet conversions, a 300% bid increase is used while doing the weighted calculation.
  • If there are no mobile conversions, but there are desktop+tablet conversions, a 100% bid reduction is used in the weighted formula.
  • For keywords that have both mobile and desktop+tablet conversions, the ratio of these is used in the weighted calculation.

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