How to use this calculator
- Enter or choose journey, first touch to last.
- Enter or choose conversion value.
- Enter or choose attribution rule.
- The channel with the most credit updates as you type. Use Copy result or Share to keep it.
Method
Last/first touch: 100% to the last/first touchpoint. Linear: 1 ÷ n each. Position-based: 40% first, 40% last, 20% shared by the middle (50/50 for two touches). Time decay: weight 2^(−steps before last ÷ half-life), normalised to 100%. Channel credit = Value × sum of its weights
- n
- number of touchpoints in the journey
- Half-life
- steps back from the last touch at which the weight halves
Worked example
- First touch (Paid search) gets 40% = $400; last touch (Email) gets 40% = $400.
- The two middle touches (Email, Social) share 20%: $100 each.
- Email total = 400 + 100 = $500 (50%); Paid search $400; Social $100.
Under the 40/20/40 rule, Email earns $500 of the $1,000 conversion, Paid search $400 and Social $100.
What the result means
Switch between rules to see how sensitive each channel’s credit is. A channel that looks strong only under last touch is mostly closing journeys others started; one that wins under first touch is mostly starting them.
Assumptions and limits
- The journey list is complete and in the right order.
- Rule-based models assign credit by convention, not by measuring causal effect. Incrementality tests or data-driven models are needed for that.
- Time decay here uses steps between touchpoints, not elapsed days.
Questions
Which model is right?
None is objectively right. Pick one that matches the question you are asking, apply it consistently, and compare against a second rule to see how robust a decision is.
Can I attribute many conversions at once?
Run one representative journey at a time, or apply the weights shown to the total value of conversions that share the same path.