Draft Beer Line Length Calculator
Balance your draft system - beer line length for your pressure, line type and rise.
Regulator pressure at serving
Vertical height from keg to faucet
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In metres-
How it works
A balanced draft system drops the full serving pressure across the beer line so the beer arrives at the tap at near-atmospheric pressure and pours without foaming. The line length needed equals the pressure to dissipate divided by the line's resistance per foot.
length(ft) = (pressure − rise × 0.5 − 1) / resistance per ft
3/16" vinyl ≈ 2.2, 1/4" vinyl ≈ 0.85 lb/ft
Sources: draft balancing method from the American Homebrewers Association.
A balancing estimate - flow rate, temperature and fittings shift the ideal. Start with this length, then trim a little at a time until the pour is right.
Frequently asked questions
- Why does my draft beer pour all foam?
- Usually the beer line is too short for the serving pressure, so the beer leaves the tap too fast and breaks out of solution. Lengthening the line adds resistance, slows the pour and cuts the foam. This calculator gives the balanced length for your setup.
- What line diameter should I use?
- 3/16" vinyl is the workhorse for home kegerators - its high resistance (~2.2 lb/ft) means short, manageable runs. Wider 1/4" or 5/16" line has far less resistance and needs much longer runs, so it is mainly for long draws and commercial trunk lines.
- Does the height of the tap above the keg matter?
- Yes. Every foot of rise costs about 0.5 PSI of head pressure lifting the beer, so a taller tower needs a slightly shorter line to stay balanced. Enter your rise to account for it.