Priming Sugar Calculator

September 6, 2025

Don’t risk a bottle bomb. Calculate your priming sugar needs with this priming sugar calculator.

NWBS Priming Sugar Calculator

Inputs

Units

US (gal / °F / oz) Metric (L / °C / g)

Amount Being Packaged

Gallons (US) or Liters (Metric)

Beer Temperature

Use the highest temp after fermentation (°F or °C) to estimate residual CO₂.

Target Carbonation (Volumes of CO₂)

2.3 vol

Tip: choose a style chip, then fine-tune with the slider.

Results

Residual CO₂ (from temp)

0.00 vol

CO₂(T) = 3.0378 − 0.050062T + 0.00026555T² (°F)

Δ CO₂ Needed

0.00 vol

Target − Residual

Beer Amount

—

Sugar	Amount	Notes

• Values are by weight, not volume. Use a scale for consistency.
• If Δ CO₂ is negative (target below residual), results show zero.

Beer Temp (for dissolved CO₂)

Your beer already has some CO₂ from fermentation, and the amount depends on temperature. Enter the highest temperature the beer reached during/after fermentation. If you cold-crashed for a long time, a bit more CO₂ may have re-absorbed—use your judgment.

Equation used (T in °F):
CO₂(vol) = 3.0378 − 0.050062·T + 0.00026555·T²

Quick CO₂ primer: “Volumes” = the volume of CO₂ at 1 atm and 0 °C relative to the volume of beer.

Don’t Over-Prime

The calculator adds sugar to move from the current CO₂ to your target. For bottling, I often use 3.5 oz (by weight) of dextrose for 5 gallons—about 2.1 volumes. More sugar = increased risk of gushers, swollen caps, and (in the worst case) bottle bombs.

Sugar notes

Corn sugar = dextrose (~91% fermentable).
Table sugar (sucrose) is 100% fermentable and works fine.
DME is an option; this tool assumes ~68% attenuation for DME.

Measure by weight (not cups)

All results are by weight. Use a scale—measuring cups trap air and vary by brand. For repeatable carbonation, weigh it.