How to calculate it
`Win Rate by Source = Opportunities Won from Source / (Opportunities Won from Source + Opportunities Lost from Source)`
Three rules keep the number honest.
Use closed opportunities only. Open pipeline in the denominator drags every source toward zero and quietly rewards channels that generate slow deals.
Lock the source at opportunity creation. An editable field records who touched the deal last, not who created it.
Cohort by creation date. A source measured on close date credits this quarter's wins to whatever the channel mix looked like two quarters ago.
Why the number moves budget
| Source | Opps created | Win rate | Cost per opp | Cost per win |
|---|---|---|---|---|
| Paid search | High | Low | Low | High |
| Partner referral | Low | High | High | Low |
| Outbound | Medium | Medium | Medium | Medium |
Source level win rate also belongs in the forecast. Pipeline weighted at a uniform stage probability assumes every opportunity converts like the average, which stops being true the moment your channel mix shifts. Sales forecasting that carries conversion rates by source reacts to a mix change in the quarter it happens rather than the quarter after.
Where the metric gets misread
Small samples. A source with a handful of closed deals produces a rate that swings on one outcome. Report the deal count beside the percentage. Segment contamination. If a source skews toward one customer segment, you may be measuring the segment rather than the channel. Split by source and segment together before rewriting a budget. Self reported versus tracked source. The two disagree often. Pick one system of record for this metric and stay on it. Deal size differences. A source can win often and still contribute less revenue than a lower converting source with larger deals. Pair the rate with average deal size before ranking channels. See win rate for the base metric and the other dimensions worth segmenting.Frequently Asked Questions
How do you calculate win rate by lead source?
Divide the opportunities won from a source by all opportunities from that source that reached a closed state, won or lost. Open pipeline stays out of the denominator. Group opportunities by their creation date rather than their close date, so the rate describes the cohort the channel actually produced instead of blending several quarters of channel mix.
How many closed deals do you need before win rate by source is reliable?
Enough that one outcome does not move the number materially. At 9 closed deals, a single win or loss swings the rate by 11 points. Publish the closed deal count next to every percentage and set a floor below which the source is reported as directional only. Sources with thin volume are better evaluated on a trailing twelve month window than on a single quarter.
Should the source field be set at first touch or at opportunity creation?
For win rate work, lock the source at opportunity creation and make the field read only afterward. If reps or automation can overwrite it later, the metric ends up recording the last channel that touched the deal rather than the one that produced it. First touch attribution belongs in marketing measurement, not in this calculation.
Why use win rate by source instead of cost per lead?
Cost per lead ranks channels on volume, and volume is the cheapest thing a channel can produce. Win rate by source converts that volume into an expected number of wins, which is what turns cost per lead into cost per closed won. Channels frequently trade places between the two rankings.
Put these metrics to work
ORM builds custom revenue forecast models that turn concepts like win rate by lead source into prescriptive action for your team.
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