Mead ABV Calculator
Choose your measurement method
Planning the next batch? Work backwards from a target strength to the honey weight with the mead recipe calculator.
Next step: Now dose your TOSNA nutrient schedule sized for your honey must.
Mead Nutrient Calculator →Why Refractometer Readings Need Correction
A refractometer measures how much light bends when passing through a liquid. Before fermentation this works perfectly for measuring sugar concentration. After fermentation, alcohol in the wash bends light differently to water — making the reading appear lower than the actual gravity. If you use the raw refractometer reading as your FG you will overestimate your ABV.
This calculator applies the Terrill correction formula, which uses both the original Brix reading and the post-fermentation apparent Brix to recover the true final gravity:
Where Ri = initial Brix (OG reading) and Rf = apparent final Brix (post-fermentation refractometer reading). This is the most widely accepted correction formula for homebrewing and home distilling.
Temperature Correction for Hydrometers
Most hydrometers are calibrated at 20°C (68°F). If your sample is warmer, the liquid is less dense and the hydrometer floats higher, giving a reading that is lower than the true gravity. The correction runs about +0.001 SG per 5°C just above calibration temperature and grows with the gap, reaching roughly +0.006 SG at 40°C. This calculator applies the polynomial correction formula for accurate results across a wide temperature range.
Honey, Nitrogen, and Why Mead Ferments Slowly
Honey is close to pure sugar. Unlike grape must or wort, it supplies almost none of the assimilable nitrogen yeast need to build healthy cell walls and finish a fermentation. This single fact drives most of what makes mead behave differently from every other ferment on this site.
Without added nutrient, a mead fermentation commonly stalls partway or drags on for months while stressed yeast throw off fusel character. Staggered nutrient additions across the first third of fermentation are the standard fix rather than a single dose at the start.
Typical range: original gravity 1.090 to 1.130, often higher for a sack mead. Final gravity for a dry mead sits below 1.000, frequently 0.995 to 1.000, because honey leaves no unfermentable dextrin behind.
At these starting gravities the simple (OG − FG) × 131.25 approximation is at its least reliable. Hall notes specifically that the full Balling-derived calculation is worth using for a mead, where the two methods diverge most.
Staggered nutrient additions sized for honey must, which supplies almost no nitrogen of its own.
Understanding Attenuation
Apparent attenuation tells you what percentage of the available sugars have been fermented. Honey ferments almost completely with a healthy yeast, so most traditional dry meads reach 95-100% apparent attenuation.
A dry mead typically reaches apparent attenuation above 95%, and readings over 100% are common because the final gravity falls below 1.000. Attenuation stalling in the 50 to 70% range on a mead points at nitrogen starvation far more often than at temperature.
SG, Brix and Plato explained — how to take accurate gravity readings at any temperature.
Wine & Mead Tasting Journal: Track your fermentation data alongside a full tasting note for every batch. 100 structured entries, score /100, buy-again rating. 6 x 9 in, 116 pages, cream paper.