Herb Drying Ratio Calculator
Calculate dried herb yield from fresh weight.
Enter herb type and fresh weight to find expected dry weight, moisture loss, and drying shrinkage ratio.
Herb Drying Ratios
Fresh herbs contain a large proportion of water — typically 70 to 90 percent of their total weight. When dried, this moisture evaporates and the herb shrinks dramatically. Understanding the fresh-to-dry ratio is essential for calculating how much fresh herb to harvest for a given dried quantity, or how much dried herb you will end up with from a fresh harvest.
Drying ratios by plant part
| Plant Material | Fresh-to-Dry Ratio | Notes |
|---|---|---|
| Leaves and flowers | 5:1 to 7:1 | High water content; wilt fast |
| Aerial parts (stem + leaf) | 5:1 | Common medicinal herbs (nettle, lemon balm) |
| Fresh roots | 3:1 to 4:1 | Denser, less water than leaves |
| Dry roots (already dry) | 1:1 | No additional shrinkage |
| Berries and fruits | 4:1 to 6:1 | Varies by species and ripeness |
| Bark | 2:1 to 3:1 | Less moisture than soft aerial parts |
| Mushrooms (fresh) | 8:1 to 10:1 | Very high water content |
How fresh-to-dry ratio works
A 5:1 ratio means 5 grams of fresh herb yields 1 gram of dried herb. Equivalently, to get 100 g of dried herb you need to start with 500 g of fresh.
Drying methods and their effects
- Air drying: slowest, preserves volatile oils best; good for aromatic herbs
- Dehydrator (35–40°C / 95–104°F): faster, retains most constituents
- Oven drying (lowest setting): quick but can degrade heat-sensitive compounds
- Freeze drying: best retention of all constituents; expensive equipment required
Most herbalists recommend air drying aromatic herbs (lavender, mint, rosemary) and dehydrator drying for roots and thick plant parts.
Calculating how much fresh herb to harvest
Divide your target dry weight by the dry fraction:
- Target dry weight: 50 g
- Ratio: 5:1 means the dry fraction is 1/5 = 0.20
- Fresh needed: 50 / 0.20 = 250 g
Storage after drying
Properly dried herbs should feel crisp and snap cleanly — not bend. Store in airtight glass jars away from light and heat. Leaves and flowers keep 1–2 years. Roots and barks keep 2–4 years. Label each jar with the herb name, plant part, harvest date, and drying method.