Sauna Bench-Space Planner
Choose how many bathers you want to seat, whether they'll sit upright or lie down, and how many bench tiers you're building, and get the linear bench length and recommended depth to plan around.
Bench length needed
Planning the layout
Bench space is the single biggest driver of how many people your sauna can comfortably hold, and it's easy to underestimate — a room that looks spacious empty can feel cramped once four or five people are seated shoulder to shoulder. Working from a per-person allowance, rather than eyeballing the wall, keeps the design honest before you cut any wood.
The classic Finnish layout uses two tiers along the same wall: a lower bench for sitting near the cooler floor air, and a higher, hotter bench above it, often built deep enough to lie on. Deciding your capacity and seating style first lets you size that wall run correctly instead of guessing and rebuilding later.
Frequently Asked Questions
How much bench space does one seated bather really need?
The standard allowance in bathhouse design is about 24 inches (61 cm) of bench length per seated adult — enough to sit upright without shoulders touching. It's a minimum for comfort, not a hard physical limit, so many builders add a little more where the room allows.
Why does lying down need so much more room?
A bather lying full-length on an upper bench needs space for their whole body, roughly 71 inches (180 cm) for an average adult, plus a bit of headroom at each end. That's close to three times the space of a seated spot, which is why lounging capacity and seated capacity aren't interchangeable.
How does a two-tier layout change the bench length I need?
A lower and upper bench stack vertically along the same wall, so they don't add their lengths together — a two-tier room with 6 seats splits into 3 per tier, each tier only needing enough length for 3 people, not 6. Two tiers let a small room seat more bathers without a longer wall run, at the cost of a taller, more layered build.
What bench depth should I build?
A seated-only bench is commonly built 20 to 24 inches deep, enough to sit with knees comfortably bent. A lounging bench needs real shoulder-to-heel depth, typically at least 24 inches and often built out to 31–35 inches so an adult can lie flat without their legs hanging off the edge.
Design and planning tool only. These are general bathhouse-design allowances for comfortable seating and lying space, not a building code requirement — check local codes and your room's actual dimensions before finalizing a layout.