Draft Beer Line Length Calculator
Foamy pours? The most common cause is a draft system that's out of balance. Plug in your applied PSI, vertical rise, and line type to get the recommended line length.
How the math works
L = (P − 1 − H × 0.5) / R
Where P is applied PSI, H is vertical rise in feet (gravity costs ~0.5 PSI per foot of climb), and R is line resistance per foot. The 1 reserves about 1 PSI at the faucet for proper pour velocity.
Vinyl line (3/16" ID, 3 PSI/ft) is the most common for home kegerators — typical setup at 12 PSI uses ~3.5 ft. Commercial bars with long runs to remote coolers use stainless or wider-ID vinyl to keep the line manageable.
Draft Line FAQ
Why does line length matter?
The beer line is what consumes the pressure between the keg and your faucet. Too short and pressure arrives at the tap too high — beer breaks out as foam. Too long and pressure drops below atmospheric — you get slow, flat pours. Balance is everything.
My beer is foamy. Is the line the problem?
Maybe. Other common foam causes: warm beer (above 40°F at the faucet), dirty lines (clean every 2 weeks), under-carbonation (recently kicked keg), or a faucet that's not fully open. If the line length matches this calculator and you're still foaming, those are the next places to look.
What's a good line length for a home kegerator?
At 12 PSI applied, with no vertical rise, using 3/16" ID vinyl line: about 3.5–4 ft. Most home kegerator kits ship with 5 ft, which is a touch long but pours well. If yours pours fast and foamy, trim 6–12 inches at a time.
Should I use vinyl or stainless?
Vinyl (commonly "Bevlex" or similar) is cheap, flexible, and standard for home/portable systems. Stainless is rigid, sanitary, and used in commercial walk-in cooler installs where lines run through walls or long horizontal runs. Stainless has lower resistance per foot, so you'll need longer runs to balance.
Pouring beer commercially?
RaspberryPints turns any TV into a digital beer menu. Show every pour with ABV, IBU, and SRM next to the beer name. Free for up to 3 taps.