Simple Spawn to Substrate Calculator

Looking for an easy way to estimate how much grain spawn and bulk substrate to use?

Our Spawn to Substrate calculator is an easy way to determine how much bulk substrate you will need based on your monotub or growing chamber.


Is this mushroom substrate calculator helpful? Have recommendations or would you like to see more detailed information? Shoot us a message on the comment box below.

Shop our best-selling pasteurized manure substrates. 

4 Comments

    1. Hey Mark, Thank you so very much for reaching out. We recently hired someone to replace our old calculator and it looks like they made a mistake in the calculation. I have gone ahead and updated this. I am sure that was frustrating and I truly appreciate you bringing it to my attention. Here is a coupon code for 10% off future purchases. Best regards, Danny

    1. I’m getting 2.9 quarts of spawn and the same for substrate. I think the weight may be a little high, but some substrates weigh more than others. This is just about what I use with shoeboxes. What numbers did you use to get 7 pounds?

Leave a Reply