# How would i go about using these number densities to get the breeding ratio?

**URL:** <https://openmc.discourse.group/t/how-would-i-go-about-using-these-number-densities-to-get-the-breeding-ratio/1180>\
**Category:** User Support\
**Created:** [May 2, 2021, 11:07am UTC](https://openmc.discourse.group/t/how-would-i-go-about-using-these-number-densities-to-get-the-breeding-ratio/1180 "2021-05-02T11:07:23Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![hhhnain](https://avatars.discourse-cdn.com/v4/letter/h/d6d6ee/32.png) [@hhhnain](https://openmc.discourse.group/u/hhhnain)\
**Post date:** [May 2, 2021, 11:07am UTC](https://openmc.discourse.group/t/how-would-i-go-about-using-these-number-densities-to-get-the-breeding-ratio/1180/1 "2021-05-02T11:07:23Z")

</div>

and do i need to include ammericium?

 ![image](https://global.discourse-cdn.com/free1/uploads/openmc/original/2X/5/5edfcdabad917d77f18e5bd7d2ee64cc308551c0.png)

---

<div class="post-metadata">

**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [June 7, 2021, 9:51am UTC](https://openmc.discourse.group/t/how-would-i-go-about-using-these-number-densities-to-get-the-breeding-ratio/1180/2 "2021-06-07T09:51:43Z")

</div>

Discussed in another thread:

> [@How to find the conversion ratio?](https://openmc.discourse.group/t/how-to-find-the-conversion-ratio/1169/7):
>
> Yes, on second thought, I think you’re better off calculating conversion rate using a a ratio of reaction rates as suggested by @gridley. Namely, the numerator (fissile material produced) can be calculated by summing the tallied (n,gamma) reaction rates for each fissionable nuclide, and the denominator (fissile material destroyed) can be calculated by summing the tallied absorption reaction rates for each fissionable nuclide.