PPC Bid Adjustment Calculator
Determine optimal bid modifiers for Google Ads and Bing Ads based on device or audience performance. Visualizes bid increases/decreases to maintain Target CPA/ROAS.
About
In Pay-Per-Click (PPC) campaigns, broad bidding strategies often waste budget on underperforming segments (e.g., Mobile vs. Desktop, or specific geographic locations). To maximize Return on Ad Spend (ROAS), advertisers must apply bid modifiers - percentage adjustments applied to the base bid - that reflect the actual value of a segment.
This tool calculates the mathematically precise Bid Adjustment (%) required to align a segment's Cost Per Acquisition (CPA) with the account average or a specific target. It eliminates the guesswork of "bumping bids by 10%" by using the ratio of conversion rates to derive the exact modifier needed to maintain profitability.
Formulas
The Bid Adjustment (Adj) is calculated by comparing the Conversion Rate of the specific segment (CRseg) against the Reference or Average Conversion Rate (CRavg):
Alternatively, if optimizing for Target CPA (CPAtarget) given a current CPA (CPAcurrent):
Reference Data
| Performance Scenario | Segment CR vs Avg | Calculated Adjustment | Action |
|---|---|---|---|
| Underperforming | 0.5x (50% of Avg) | -50% | Decrease Bid |
| Slightly Below | 0.8x (80% of Avg) | -20% | Decrease Bid |
| Average | 1.0x (Parity) | 0% | No Change |
| High Performance | 1.2x (120% of Avg) | +20% | Increase Bid |
| Top Performer | 1.5x (150% of Avg) | +50% | Increase Bid |
| Unicorn | 2.0x (200% of Avg) | +100% | Double Bid |
| Wasteful | 0.0x (No Conv) | -100% | Exclude/Negate |