What temperature should I enter?

Enter the highest temperature your beer reached after active fermentation ended — typically the temperature it sat at during secondary fermentation or cold crashing. Beer retains CO2 from that peak temperature even after chilling, so using a lower temp than actual gives too much priming sugar and can cause over-carbonation.

What are typical CO2 volumes by style?

American ales: 2.2–2.7 volumes. British ales: 1.5–2.2. Belgian ales: 2.8–3.8. German wheat beers: 3.0–4.5. Lagers: 2.4–2.8. American stouts: 1.8–2.5. Use the middle of the range as a starting point.

Why does temperature affect residual CO2?

CO2 is more soluble in cold liquid. Beer that fermented warm holds less dissolved CO2 than beer that fermented cold. If you ignore residual CO2 and add a full priming dose, the beer will be over-carbonated because the CO2 already present adds to what the sugar produces.

Is corn sugar, table sugar, or DME best for priming?

Corn sugar (dextrose) is the homebrewing standard — it is 100% fermentable and leaves no flavor. Table sugar (sucrose) works equally well at a slightly lower dose because it is denser by weight. DME adds a tiny malt note and requires about 50% more by weight because it is only ~60–65% fermentable sugars. All three give clean results if measured accurately.

Can I use this for kegging with CO2 force carbonation?

This tool calculates priming sugar for natural carbonation in sealed containers (bottles or kegs). For force carbonation from a CO2 tank, you need a pressure/temperature chart (set PSI based on your target volumes at serving temperature), not priming sugar amounts.

How accurate is the residual CO2 formula?

The polynomial formula (Volumes = 3.0378 − 0.050062 × T + 0.00026555 × T²) matches published absorption tables to within ±0.05 volumes across the 32–80°F range. It is the same formula used in BrewUnited, BrewCalc, and referenced in John Palmer's "How to Brew."

CO2 Volumes Calculator for Homebrewing

Name: CO2 Volumes Calculator for Homebrewing
Availability: InStock
Author: Nham Vu

Enter your beer temperature and target CO2 volumes to calculate residual CO2 and the exact priming sugar needed to carbonate your batch.

Carbonation Inputs

Beer Temperature (highest post-fermentation temp)

Batch Size

Target CO2 Volumes

American ales 2.2–2.7 • Lagers 2.4–2.8 • Belgian ales 2.8–3.8 • Wheat beers 3.0–4.5

Style Presets

CO2 Analysis

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Residual CO2

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Volumes Needed

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Target Volumes

Priming Sugar Amounts

Corn Sugar (Dextrose)

100% fermentable, neutral flavor

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Table Sugar (Sucrose)

100% fermentable, slightly denser

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Dry Malt Extract (DME)

~62% fermentable, adds malt note

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Tip: Dissolve priming sugar in ~1 cup of boiled water, cool, and gently stir into the beer before bottling. Cap immediately and condition at 65–72°F for 2–3 weeks.

Summary

Enter your beer temperature and target CO2 volumes to calculate residual CO2 and the exact priming sugar needed to carbonate your batch.

How it works

Enter the highest temperature your beer reached after active fermentation (the conditioning temperature in °F or °C).
Enter your batch size in US gallons or liters.
Enter the target CO2 volumes for your beer style (e.g. 2.4 for American ales, 3.0 for German wheat beers).
The calculator derives residual CO2 already dissolved at that temperature using the standard absorption formula.
It subtracts residual CO2 from the target to find the additional volumes needed from priming sugar.
Priming sugar amounts for corn sugar, table sugar, and DME are displayed for your batch size.

Use cases

Calculate how much corn sugar to add when bottling a batch of IPA.
Determine DME priming amounts for a Belgian witbier targeting 3.2 volumes.
Verify that a cold-conditioned lager already has enough residual CO2 before kegging.
Compare priming sugar types to find the most convenient option for your setup.
Adjust carbonation targets for different bottle sizes or yeast strains.
Avoid over-carbonation (bottle bombs) by using accurate residual CO2 values.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu