You can use these calculators to calculate the mash and the international bitterness unit (IBU).
Hop Bitterness Calculator
Find out the estimated Bittering Units (BU) in your homebrew.
Brewhouse Efficiency Calculator | Brewer's Friend
Reports beer mash extraction efficiency in percentage terms and points per pound per gallon (ppg). Useful for all grain beer brewers to calculate their actual efficiency at extracting sugars from the grain during the mash.
IBU Calculator Beer Bitterness | Brewer's Friend
This IBU calculator reports how bitter your beer will be given up to six hops additions. It works for all grain, partial mash and extract style recipes.
Mash Infusion and Rest Schedule Calculator | Brewer's Friend
Infusion mash calculator with rest steps. Use this calculator to find out your strike water temperature and volume, and if you are performing additional rests you can plan them out in advance.
Quick Infusion Calculator for Mashing | Brewer's Friend
Finds the amount of boiling water needed to reach a new rest temperature in your mash tun. For use in the middle of mashing.