Signal PPC

Marketing Performance Diagnostic

Compare two reporting periods and get a deterministic, rule-based breakdown of what changed, the exact mathematical drivers behind it, and plausible real-world causes to investigate.

Enter whatever metrics you have for each period — you don't need all of them. Fill in raw counts (spend, impressions, clicks, conversions, revenue) and/or rates (CTR, CPC, CPM, conversion rate, CPA, ROAS) directly; the diagnostic derives anything else the math allows.

Previous Period

Or enter rates/ratios directly

Current Period

Or enter rates/ratios directly

Executive Summary

KPI Comparison

MetricPreviousCurrentChange% Change

Biggest Changes

    Mathematical Drivers

      Possible Explanations

      Recommended Investigations

        Important Limitations

          How This Works

          This tool runs entirely in your browser — nothing you enter is sent to a server or stored anywhere. It uses a fixed set of deterministic formulas and rules, not an AI model, to:

          • Derive any of the 11 supported metrics that the math allows from what you entered (e.g. Spend + Clicks → CPC).
          • Flag it — rather than silently picking one — if two entered values contradict each other.
          • Compute the exact, non-approximated relationship between metrics (e.g. CPA = Spend ÷ Conversions, so a 30% spend increase and a 5% conversion increase produce a 23.8% CPA increase — not 25%, which naive percentage-point subtraction would wrongly suggest).
          • Suggest hedged, plausible real-world causes for whichever relationships the data actually supports — never asserted as confirmed fact.

          This is not causal analysis. It tells you precisely what moved and how the pieces relate to each other mathematically. Confirming why requires looking at your actual account, campaigns, and tracking setup.

          Related Calculators

          Paid Media

          ROAS Calculator

          Calculate your return on ad spend from spend and revenue.

           Paid Media

          CPA Calculator

          Calculate your cost per acquisition from ad spend and conversions.

           Paid Media

          Marketing Budget Pacing Calculator

          Check whether a campaign is on pace to spend its budget, and find the required daily spend.

          Related Articles

          Marketing Analytics & Attribution

          How to Analyze Week-Over-Week Campaign Performance

          A practical walkthrough for comparing two reporting periods without jumping to conclusions — what to look at first, and how to use a structured diagnostic instead of guessing.

           Google Ads & Paid Media

          Why CPA Increases Even When Conversions Increase

          CPA can rise even while conversions grow, if spend grows faster. Here's the exact math behind it, and how to tell whether traffic cost or conversion efficiency is driving it.