Food Drying Yield Calculator (Dehydrator: Dried Weight from Fresh)
How much a batch weighs once dried, how much water has to go, the share of the weight that remains, and how much fresh food makes a given amount of dried.
Results
The dashed line marks the value you entered.
What this tool does
Drying removes water but none of the solids, so the dry matter stays the same: dried weight = fresh weight × (100 − initial water %) ÷ (100 − final water %). Fruit and vegetables are mostly water — often 80–95 % — so an apple at 85 % water dried down to 15 % keeps only about 18 % of its weight, and it takes roughly 5.7 kg of fresh fruit to make 1 kg of dried. Use the figure from a tray weighed before and after drying to check how far along a batch is. How dry is dry enough for safe storage depends on the food; follow food-safety guidance for that product.
Formula
dried weight = fresh weight × (100 − initial water %) ÷ (100 − final water %)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
m | Weight of fresh food | g |
mi | Water in the fresh food | % |
mf | Water you want left after drying | % |
D | Weight after drying | g |
W | Water to dry off | g |
Y | Share of the weight left | % |
F | Fresh food needed for 100 of dried | — |
Worked example
- Weight of fresh food1000 g
- Water in the fresh food85 %
- Water you want left after drying15 %
- Weight after drying176.5 g
- Water to dry off823.5 g
- Share of the weight left17.6 %
- Fresh food needed for 100 of dried567
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.