How to calculate attach rate
Attach rate tracks how successfully you sell complementary products, modules, or services alongside the main product. It is a direct lever on deal value and a sign of how well your packaging and reps position add-ons.
It is common wherever there are natural add-ons: premium support, additional modules, onboarding services, or usage tiers. Raising attach rate lifts deal size without needing more customers.
- Add-on / core units The formula
- Raises deal value Why it matters
- Packaging + reps What drives it
Short answer
Attach rate measures how often an add-on sells alongside a core product. Divide the number of add-on units (or attaching deals) by the number of core product units sold, then multiply by 100. If 40 of 100 core deals included a premium support add-on, the attach rate is 40 percent. Higher attach rates raise average deal value.
Step by step
Identify the core and add-on
Define the core product and the specific add-on, module, or service whose attach rate you want to measure.
Count core and add-on units
Count the units of the core product sold and the units of the add-on sold (or deals that included it) in the period.
Divide add-on by core
Attach rate equals add-on units divided by core units, times 100. A rate above 100 percent is possible if customers buy multiple add-ons per core unit.
Segment and act
Break attach rate out by rep, segment, and channel. Low attach often means the add-on is not being positioned; better packaging or enablement raises it.
Worked example
In the quarter you sold 200 core subscriptions. Of those deals, 70 included a premium support add-on and 50 included an onboarding package.
Premium support attach rate = 70 / 200 = 35 percent; onboarding attach rate = 50 / 200 = 25 percent. If the premium add-on carries high margin, lifting its attach from 35 to 50 percent through better positioning would raise average deal value meaningfully with no new customers.
How Ardovo handles it
Ardovo tracks attach rate by add-on, rep, and segment, so you see which reps and motions position add-ons well. Rook flags deals where a common add-on was not attached, prompting reps to include it before close.
Frequently asked questions
What is the attach rate formula?
Units of an add-on sold divided by units of the core product sold, times 100. It measures how often a complementary product, module, or service sells alongside the core, a direct lever on average deal value.
Why does attach rate matter?
Because raising it increases average deal value without acquiring more customers. A higher attach rate on high-margin add-ons is one of the most efficient ways to grow revenue per deal, driven by packaging and rep positioning.
How do I improve attach rate?
Bundle or default the add-on into packaging, train reps to position it, and make its value obvious at the point of sale. A low attach rate usually means the add-on is not being surfaced, not that customers do not want it.