Rehydration
Rehydration Calculator
This is the entry point to the canonical Rehydration Calculator, which lives in the Rehydration Center. The full tool works two ways: from fresh and dry weights it estimates the water removed and a starting rehydration amount, and in package mode it subtracts packaging to find the net food weight first.
What the Rehydration Calculator Does
The calculator is a working tool, not a placeholder, and it already lives at the Rehydration Center:
Fresh vs Dry Weights
Enter a fresh weight and a freeze-dried weight in the same unit. You get the approximate water removed, the weight reduction, the dry yield and a starting rehydration water estimate based on the 1 g of water is about 1 mL kitchen rule.
Package Mode
Weighed a sealed pouch? Subtract the total package weight, bag weight, oxygen absorber and other packaging to find the net freeze-dried food weight, then optionally apply a water ratio you enter yourself.
Starting Water Estimate
Every result is labeled a starting estimate, never an exact amount. Adjust by texture and taste, and record the ratio that worked for next time.
Opens in the Rehydration Center at /rehydration/calculator/. Everything runs in your browser.
Why It Lives in the Rehydration Center
Rehydration is part of the Rehydration Center's subject matter, and the calculator sits next to the guides that explain how to use its numbers: how much water to add, how texture is the final judge, and how to record the ratio that worked. This page is the Tools Center entry point that points you to it, so there is only one canonical calculator and no duplicate numbers to conflict.
Important Limitations
- The calculator gives a calculated estimate from weights you enter, not a tested, exact requirement.
- The 1 g of water is about 1 mL approximation applies to water, not oils, syrups or milk.
- Food structure, fat, sugar, cooking method and desired texture all change how much water a food really wants: adjust by texture and taste.