Formulas

Conversion rate from GA4 in Google Sheets

Key events over sessions, why it won't match GA4's own rate, and the averaging trap.

About the Google Analytics 4 connector

Conversion rate is the share of visits that end in something you care about. GA4 calls those somethings key events: it's what it used to call conversions.

The formula

Conversion rate = key events ÷ sessions

In Google Sheets, with sessions in column B and key events in column C:

=IF(B2=0, "", C2/B2)

Format the column as a percentage.

A worked example

The total row is:

=SUM(C2:C4)/SUM(B2:B4)

Why it won't match GA4's own rate

GA4's Session key event rate counts sessions that contained at least one key event. Key events divided by sessions counts the events themselves, so a session with two purchases counts twice. Neither is wrong; use the one that matches your question, and label it.

Never average rates

=AVERAGE(D2:D4) returns 3.00%. The correct figure is 2.80%.

Paid Search converts best but brings the fewest sessions, so weighting every channel equally flatters the total. Divide total key events by total sessions instead.

Keeping the inputs current

A scheduled Fresh Sheets GA4 report by Channel group, or by Date, with Sessions and the key event you care about, keeps both inputs current. Each key event you pick is headed with the name GA4 gives it. Calculate the rate yourself from those two columns rather than picking a ready-made rate, so you know exactly what's being divided by what.

Keep your formulas on a separate tab, since the report replaces its own tab on every refresh.