Mash Step Calculator

mash step volume and temperature calculators.

If you're using our recipe page, you'll shortly not need to worry about this calculator as you'll be able to work it out from your recipe.

If you're doing a single step mash with a mash out, you'll not need this calculator. If you're step mashing in your mash tun, this is what you're looking for.

You'll need to enter the following data:

  • Weight of Grains: the total grains in your mash tun
  • Mash Thickness: the current thickness of your mash - how many litres you added to the current mashing step/the weight of grains.
  • Mash Tun Deadspace: all the hidden/wasted space in your mash tun
  • Mash Tun Equivalent Water Volume: the amount of water equivalent of your mash tun. You can work this figure out in the mash tun calibrate page.
  • Current Temperature: the current step temperature
  • Target Temperature: the target step temperature

You need to add only one of these as you're calculating either the amount of water (at a specified temperature) to add, or the temperature of the water (of a specified volume) to add:

  • Water Temperature: the temperature of the water you're adding
  • Step Volume: the volume of the step you're adding

The Results

  • Volume of Mash Step Water Needed: how much water you need to add to the tun (when you've specified Water Temperature above) to achieve the target temperature.
  • Step Water Temp: how hot the water needs to be (when you've specified the Step Volume) to achieve the target temperature.
  • Volume Equivalent in Tun: how much volume is in your tun after the addition. Useful in understanding whether you've exceeded it's capacity.


  • [ ] Add mash step water volume calculator to recipe.

James Torr 18 Jun 22