Keg Line Balancing Calculator — Perfect Draught Beer at Home
Use this free keg line balancing calculator to work out the correct beer line length for your home draught system. Enter your CO₂ pressure, tap height, and line type — and the calculator gives you the line length needed for a perfect, steady pour without excessive foam or flat beer.
Why does beer line length matter?
Beer line length controls the resistance in your draught system. If your line is too short, CO₂ pressure pushes beer through too quickly — you get excessive foam and flat-tasting pints. If the line is too long, the pour is slow and sluggish. The correct line length creates just enough resistance to balance your serving pressure, giving you a smooth, steady pour with a proper head.
What pressure should I serve home brew beer at?
Most home brew ales and bitters are best served at 0.5–0.8 bar (7–12 psi). Lagers typically need slightly more — around 0.8–1.0 bar. The right serving pressure depends on your carbonation level: the higher the carbonation, the more pressure you need to maintain it without the beer going flat or foaming excessively.
What beer line should I use for a home keg setup?
For most home draught setups, 3/16" (4.75mm ID) vinyl or polyethylene beer line is standard. It has enough resistance per metre that you can keep lines at a practical length (1–3 metres) while still balancing typical serving pressures. Wider bore lines (1/4") have much lower resistance and require very long runs to balance — not practical for home use.
How do I know if my line is the right length?
A well-balanced system pours at roughly 1 pint per 10 seconds — steady and smooth with a 1–2cm head. If beer foams immediately when you open the tap, your line is too short or pressure too high. If the pour dribbles or stops, the line is too long or pressure too low. Use this calculator as your starting point, then fine-tune by adjusting pressure by 0.1 bar at a time.
More free home brew calculators
- Priming Sugar Calculator — how much sugar to add when bottling beer or cider
- ABV Calculator — calculate alcohol content from gravity readings
- Keg Carbonation Calculator — target CO₂ volumes for force carbonating
- Strike Temperature Calculator — hit your mash temperature first time
Browse our full range of King Keg pressure barrels and keg spare parts at BrewCo UK. Based in Sowerby Bridge, Halifax — free UK delivery over £65.