01
How to use this ABV calculator
Pick your beverage first — beer, wine, or cider. That sets sensible default readings and the reference table, but the alcohol maths is identical for all three. Then choose your measurement mode: specific gravity if you use a hydrometer, or Brix if you use a refractometer.
Enter your original gravity and final gravity and the tool instantly returns estimated ABV, apparent attenuation, gravity drop, a strength band, and an approximate calorie count per serving. Use those numbers to decide whether fermentation is still active, near its terminal gravity, or ready to package.
02
The ABV formula behind the tool
The standard estimate is ABV = (OG − FG) × 131.25. Specific gravity tracks dissolved sugar concentration, and fermentation converts that sugar into ethanol and carbon dioxide. As gravity falls, alcohol rises, so the size of the drop maps directly onto alcohol content.
This method is fast and is the reference most homebrewers use. It is still an estimate — a slightly different multiplier and more complex equations exist for very high-gravity worts and wines — but for beer, cider, and most wine it is accurate enough for recipe tuning, batch logs, and packaging decisions.
Worked exampleOG = 1.050 and FG = 1.010Gravity drop = 0.040ABV = 0.040 × 131.25 = 5.25%
03
How to read OG and FG correctly
Measure original gravity after all sugar is fully dissolved and mixed, but before pitching yeast. Pull a sample into a test jar, spin the hydrometer to shed bubbles, and read at the base of the meniscus. Note the sample temperature, since hydrometers are calibrated to a specific reference temperature.
Measure final gravity only once fermentation appears to slow, then confirm with a repeat reading two to three days later. If the number holds steady, fermentation is functionally done. If it is still falling, the yeast are still working — do not package a beer, wine, or cider that is still dropping gravity unless you are deliberately conditioning in a pressure-rated vessel.
04
Brix readings and refractometer correction
Refractometers are excellent before fermentation, but once alcohol is present a raw Brix reading no longer represents sugar concentration on its own. That is why fermented Brix must be corrected using both the original and current Brix values. Skip the correction and your FG — and therefore ABV — will be wrong.
Use Brix mode when you do not have hydrometer readings for the same batch stage. Many brewers log refractometer readings during active fermentation for convenience, then take a final hydrometer reading to confirm terminal gravity before packaging.
05 Quick compare
Beer vs wine vs cider: what changes
The formula does not change between beverages, but the typical starting gravity does. Beer and cider usually begin in the 1.045–1.070 range and finish 4–8% ABV. Wine starts higher, often 1.080–1.110, and finishes 11–14% or more, frequently fermenting at or below 1.000 for a dry style.
The reference table in the calculator updates to the beverage you select, so you can sanity-check your readings against common styles. If your gravity sits far outside the listed range, re-check your measurement before trusting the ABV number.
Beer OG ~1.045–1.070, FG ~1.010, ABV 4–7.5% for most ales and lagers.
Cider OG ~1.045–1.065, FG ~1.000–1.010, ABV 5–8% depending on sweetness.
Wine OG ~1.080–1.110, FG ~0.990–1.005, ABV 11–14% for dry styles.
High-gravity Barleywines, sack wines, and strong ciders push 9–14%+ and need aging.
06
Attenuation, dryness, and body
Apparent attenuation is the proportion of fermentable sugar consumed. High attenuation usually means less residual sugar and a drier, thinner-bodied result; low attenuation leaves more sweetness and body. Beers often land 70–80%, ciders and wines frequently push higher because their sugars are more fully fermentable.
Treat attenuation as a process signal rather than a flavour guarantee. Two beers can both attenuate near 80% yet taste different depending on mash temperature, acidity, and carbonation. Read it alongside tasting notes and your gravity log rather than in isolation.
07
ABV targets by beverage
Session beers target 3–4.5% for easy drinking; standard ales and lagers land 4.5–6%; strong ales, IPAs, and barleywines run 8–12%. Dry ciders usually finish 6–8%, while stronger New England styles reach 9–12%. Table wines commonly target 11–14%, with dessert styles higher.
Set your target from the style you want, your yeast’s alcohol tolerance, and your timeline. Higher ABV is not automatically better — it lengthens conditioning time and can amplify fusel heat if the yeast is stressed. Beginners often get cleaner results aiming for the middle of a style’s range and prioritising healthy fermentation.
08
Troubleshooting odd ABV outcomes
If ABV looks too low, check whether OG was taken before the sugar fully dissolved, whether FG was read too early, or whether you skipped temperature correction. If ABV looks unusually high, verify decimal placement, calibrate your hydrometer in plain water, and confirm you did not transpose readings in your notes.
When a value still looks wrong, degas the sample, pull a fresh reading, and repeat. Clean logs — OG, gravity checkpoints, temperature, and yeast — make diagnosis far easier than reconstructing a batch from memory after it is finished.
