OG Estimator
Plan your recipe before you pitch: add your ingredients and batch volume to estimate original gravity, potential ABV and Brix.
Wine / beverage type
Estimated OG
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A starting-point estimate: actual gravity depends on the exact sugar content of your ingredients.
How it works
Each ingredient contributes fermentable sugar based on its weight and sugar percentage. The calculator totals the effective sugar across all ingredients (plus any additional sugar you add directly), divides it by your batch volume, and converts that concentration into an estimated original gravity, the same approach used by the OG estimator in the Fermolog app.
Different beverage types default to different sugar sources: honey for mead, malt extract for beer, fruit sugars for wine and cider, since they ferment differently and are dosed differently.
Default sugar % by beverage type
Each beverage type pre-fills a typical sugar concentration when you add an ingredient, which you can always override with your own reading.
| Beverage type | Default sugar % |
|---|---|
| Mead | 80% |
| Fruit wine | 16% |
| Grape wine | 22% |
| Cider | 12% |
| Perry | 10% |
| Fruit cider | 14% |
| Beer | 75% |
| Ginger beer | 10% |
Frequently asked questions
How do I estimate OG before I even start fermenting?
Add each fermentable ingredient (honey, sugar, malt extract, fruit, juice concentrate) with its weight and sugar percentage, plus your target batch volume. The calculator converts the total fermentable sugar into an estimated original gravity, so you can plan a recipe before you buy ingredients or take a hydrometer reading.
What sugar percentage should I use for honey or fruit?
This calculator pre-fills a reasonable default sugar percentage per beverage type (for example honey for mead), which you can edit per ingredient. Actual sugar content varies by honey variety, fruit ripeness and product batch, so treat the result as a planning estimate rather than a lab-accurate number.
Why does my actual hydrometer reading differ from the estimate?
This estimator assumes typical sugar concentrations and full solubility. Real ingredients vary, and factors like fruit water content, incomplete dissolving or non-fermentable solids all shift the actual reading. Once you take a real OG measurement, use it going forward; this tool is for planning before you start.
Related tools
Track the whole batch, not just the math
Fermolog logs your gravity readings, ABV, notes and photos automatically as you go. Download the free app to keep every batch in one place.