Beer Carbonation Calculator

Why correct CO2 pressure matters for draft beer

Carbonation is set at the brewery and must be maintained through your entire draft system. Too little CO2 pressure and the beer goes flat; too much and it becomes over-carbonated and foamy. The right PSI depends on four variables: beer temperature, target volumes of CO2, elevation above sea level, and the gas blend you're using.

This beer carbonation calculator implements the BA Table 3.2 equilibrium pressure data with bilinear interpolation for precise results anywhere in the range. It accounts for blended gas systems (70/30, 25/75, custom blends) by calculating the CO2 partial pressure — the actual pressure that determines carbonation — and then scaling up to the total regulator pressure needed.

How the carbonation calculation works

The calculator uses two methods, each authoritative in its range:

• BA Table lookup — For temperatures 33–42°F and volumes 2.1–3.1 vol CO2, the result is interpolated from the official BA equilibrium pressure table for exact, published values.
• Henry's Law formula — For values outside the BA table range, the calculator falls back to a temperature-and-volume polynomial based on Henry's Law, which governs gas solubility in liquids.
• Elevation correction — Add 1 PSI per 2,000 ft above sea level (accounting for lower atmospheric pressure at altitude, which reduces the effective carbonation pressure).
• ABV adjustment — Higher-ABV beer is slightly less CO2-soluble. The calculator applies approximately +0.2 PSI per 1% ABV above 5% baseline.

Select your style preset or enter exact values below, then click Calculate CO2 Pressure to get the precise regulator setting. Shop our CO2 and blended gas regulators to dial it in.

Understanding volumes of CO2

Volumes of CO2 is the standard measure of carbonation in beer. One volume of CO2 means one gallon of beer contains one gallon of dissolved CO2 gas at standard temperature and pressure. Typical ranges:

• 1.2–1.6 vol — Cask ales, nitro stouts (low carbonation, requires stout faucet)
• 2.0–2.2 vol — Porters, brown ales, ambers (moderate carbonation)
• 2.4–2.6 vol — Pale ales, IPAs, American lagers (standard carbonation)
• 2.8–3.2 vol — Belgian ales, hefeweizens, saisons (high carbonation)
• 3.5+ vol — Lambics, gueuzes (very high, champagne-like)